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PHYSICS, RADBIO, RADPRO,IEM,ISI
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PHYSICS, RADBIO, RADPRO,IEM,ISI

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Questions and Answers

What does the symbol 'p' represent in the context of momentum?

  • Total momentum (correct)
  • Pressure
  • Energy
  • Power

    • What is the formula for calculating work?

  • W = (p)(t)
  • W = (F)/d
  • W = (F)(d) (correct)
  • W = (m)(v)

    • Which of the following represents the unit for power?

  • Joule per second (correct)
  • Joule
  • Watts per second
  • Newton

    • What is conduction primarily concerned with?

    <p>Transfer of heat by touching</p> Signup and view all the answers

    What describes thermal radiation?

    <p>Transfer of heat through electromagnetic waves</p> Signup and view all the answers

    What did the Crookes tube contribute to the development of modern technology?

    <p>It was a precursor to the fluorescent lamp and X-ray tube.</p> Signup and view all the answers

    Who received the Nobel Prize in Physics in 1901 for work related to X-rays?

    <p>Wilhelm Roentgen</p> Signup and view all the answers

    Which inventor introduced the coolidge X-ray tube in 1913?

    <p>William Coolidge</p> Signup and view all the answers

    What type of images does fluoroscopy provide?

    <p>Moving/dynamic images</p> Signup and view all the answers

    Which inventor is associated with the invention of the stationary grid, also known as 'glitterblende'?

    <p>Gustav Bucky</p> Signup and view all the answers

    What was the primary measurement unit associated with X-ray current?

    <p>mA</p> Signup and view all the answers

    What significant advancement did the light amplifier achieve in fluoroscopy in 1946?

    <p>Adaptation for fluoroscopy</p> Signup and view all the answers

    Which of the following is an example of a special quantity?

    <p>Exposure dose</p> Signup and view all the answers

    What is the unit of measure for X-ray voltage?

    <p>kVp</p> Signup and view all the answers

    Which base quantity is NOT mentioned among the three primary ones?

    <p>Temperature</p> Signup and view all the answers

    What is the behavior of gamma rays in terms of their origin?

    <p>They are emitted spontaneously from radioactive material.</p> Signup and view all the answers

    Which of the following describes x-rays in terms of radiographic appearance?

    <p>They appear black in the radiograph.</p> Signup and view all the answers

    What happens to the density of a radiograph if the source-to-image distance (SID) is doubled?

    <p>Density is reduced to 1/4.</p> Signup and view all the answers

    What is true about the nature of x-rays?

    <p>They are polyenergetic and heterogeneous.</p> Signup and view all the answers

    Which of the following statements is correct regarding the inverse square law?

    <p>The intensity of radiation is inversely proportional to the square of the distance.</p> Signup and view all the answers

    What effect does a long distance from a radiation source have on radiographic density?

    <p>It decreases density.</p> Signup and view all the answers

    What is the SI unit for electric potential?

    <p>Volt (V)</p> Signup and view all the answers

    In Max Planck's quantum theory, what identifies x-rays?

    <p>Their energy measured in eV.</p> Signup and view all the answers

    Which law states that electric charge distribution is uniform on the surface of a conductor?

    <p>Law of Distribution</p> Signup and view all the answers

    What occurs when unlike charges come in proximity to each other?

    <p>They attract each other.</p> Signup and view all the answers

    What is the primary method of cooling for an x-ray tube?

    <p>Radiation</p> Signup and view all the answers

    Which unit measures the amount of radiation exposure?

    <p>Roentgen</p> Signup and view all the answers

    What does 'rad' correspond to in SI units?

    <p>Gyt</p> Signup and view all the answers

    What did Dalton contribute to atomic theory?

    <p>Classified elements by atomic mass</p> Signup and view all the answers

    What does the term 'equivalent dose' refer to?

    <p>The quantity of radiation received by radiation workers</p> Signup and view all the answers

    In Neil's Bohr atomic model, how do electrons move?

    <p>In fixed, well-defined orbits</p> Signup and view all the answers

    What is the main component of Ernest Rutherford's nuclear model?

    <p>Electrons encircle a dense nucleus</p> Signup and view all the answers

    Which particle carries a positive charge?

    <p>Proton</p> Signup and view all the answers

    Which of the following best describes the term 'atomic mass unit'?

    <p>The mass of a neutral atom of an element</p> Signup and view all the answers

    What does 'effective dose' measure?

    <p>Dose taking into respect the type of radiation</p> Signup and view all the answers

    What did Joseph John Thomson contribute to atomic science?

    <p>Developed the Plum Pudding model</p> Signup and view all the answers

    How are neutrons characterized in an atom?

    <p>They have mass but no charge.</p> Signup and view all the answers

    Which of the following quantities is measured in Sieverts?

    <p>Equivalent dose</p> Signup and view all the answers

    What is the significance of mass in atomic structure?

    <p>Mass is primarily located in the nucleus.</p> Signup and view all the answers

    What is the role of a high voltage generator in x-ray production?

    <p>Increases the output voltage from the autotransformer</p> Signup and view all the answers

    Which law describes the relationship between voltage and the number of turns in a transformer?

    <p>Autotransformer Law</p> Signup and view all the answers

    What is the main purpose of a timer circuit in x-ray systems?

    <p>To manage the high voltage across the x-ray tube</p> Signup and view all the answers

    Which of the following describes thermionic emission?

    <p>The release of electrons from a heated filament</p> Signup and view all the answers

    How is the filament temperature controlled in an x-ray tube?

    <p>Through the filament circuit</p> Signup and view all the answers

    What is a primary advantage of using a falling load generator?

    <p>It begins exposure at maximum mA for minimum time.</p> Signup and view all the answers

    Which of the following correctly describes full-wave rectification?

    <p>It contains at least two diodes.</p> Signup and view all the answers

    What does an Automatic Exposure Control (AEC) measure?

    <p>The quantity of radiation reaching the image receptor</p> Signup and view all the answers

    What is the effect of using a three-phase power supply in x-ray systems?

    <p>It produces a nearly constant voltage across the x-ray tube.</p> Signup and view all the answers

    In x-ray systems, what is the typical unit of measurement for radiation quantity?

    <p>Milliroentgens (mR)</p> Signup and view all the answers

    What type of semiconductor is characterized by loosely bound electrons?

    <p>P-type semiconductor</p> Signup and view all the answers

    Which device is responsible for isolating filament heating in x-ray systems?

    <p>Filament transformer</p> Signup and view all the answers

    Which of the following statements minimizes the patient radiation dose?

    <p>Utilizing an Automatic Exposure Control (AEC).</p> Signup and view all the answers

    What is the function of precision resistors in the x-ray system?

    <p>To reduce voltage to a specific value for milliamperage.</p> Signup and view all the answers

    What is the primary difference between mass and weight?

    <p>Mass is the quantity of matter, while weight is the force exerted on that mass by gravity.</p> Signup and view all the answers

    Which type of radiation is capable of removing electrons from atoms?

    <p>Ionizing Radiation</p> Signup and view all the answers

    What term describes the energy transformation that cannot be created or destroyed?

    <p>Law of Conservation of Energy</p> Signup and view all the answers

    Which of the following is an example of kinetic energy?

    <p>A moving car</p> Signup and view all the answers

    What is the largest source of natural ionizing radiation exposure for humans?

    <p>Radon</p> Signup and view all the answers

    What unit is commonly used to measure energy in radiology?

    <p>Electron Volt</p> Signup and view all the answers

    Which historical figure is credited with the discovery of X-rays?

    <p>Wilhelm Roentgen</p> Signup and view all the answers

    What type of radiation is primarily emitted by nuclear medicine procedures?

    <p>Gamma Rays</p> Signup and view all the answers

    What is the primary purpose of radioactive decay?

    <p>To transform into a more stable atom</p> Signup and view all the answers

    Which decay mode results in a decrease in atomic number by 1?

    <p>Beta plus decay</p> Signup and view all the answers

    What type of energy is derived from the position of an object?

    <p>Potential Energy</p> Signup and view all the answers

    How does the annual dose of man-made radiation compare to natural radiation?

    <p>Slightly higher than natural radiation</p> Signup and view all the answers

    What happens during beta plus decay?

    <p>A proton is converted to a neutron</p> Signup and view all the answers

    Which type of decay is characterized by the release of gamma rays?

    <p>Gamma decay</p> Signup and view all the answers

    What is the role of half-life in radioactivity?

    <p>It indicates the time taken to reduce radioactivity to half its original value</p> Signup and view all the answers

    Which particle is emitted during beta minus decay?

    <p>Negatron</p> Signup and view all the answers

    What characterizes alpha decay?

    <p>Loss of mass and electrical charge</p> Signup and view all the answers

    What defines the term 'radionuclide'?

    <p>Atoms involved in radioactive decay</p> Signup and view all the answers

    In electron capture, which transformation occurs?

    <p>A proton captures an electron to become a neutron</p> Signup and view all the answers

    Which of the following statements best describes gamma decay?

    <p>It releases energy without changing atomic number</p> Signup and view all the answers

    What characteristic defines a superconductor?

    <p>Exhibits no resistance below a critical temperature</p> Signup and view all the answers

    Which material is classified as a conductor?

    <p>Titanium</p> Signup and view all the answers

    What is the function of a film badge in radiation monitoring?

    <p>To detect and measure radiation exposure</p> Signup and view all the answers

    What is the primary function of an insulator in an electrical circuit?

    <p>Prevents electron flow</p> Signup and view all the answers

    Which device is primarily used to measure high radiation exposure and provide immediate readings?

    <p>Pocket Dosimeter</p> Signup and view all the answers

    What does Ohm's Law state regarding voltage, current, and resistance?

    <p>Voltage is equal to current times resistance</p> Signup and view all the answers

    What does lithium fluoride (LiF) in a thermoluminescent dosimeter do during radiation exposure?

    <p>Stores the energy associated with exposure</p> Signup and view all the answers

    In which condition does a semiconductor operate predominantly as an insulator?

    <p>At high temperatures</p> Signup and view all the answers

    Which of the following detectors can distinguish between different types of radiation such as alpha and beta?

    <p>Proportional Counters</p> Signup and view all the answers

    What is the recommended minimum distance an operator should maintain from the x-ray tube during exposure with a mobile x-ray imaging system?

    <p>2 meters</p> Signup and view all the answers

    What is meant by the term 'electric current'?

    <p>The flow of electrons through a conductor</p> Signup and view all the answers

    Which component of a pocket dosimeter indicates the radiation quantity in milliroentgen (mR)?

    <p>Fiber indicator</p> Signup and view all the answers

    Which of the following statements is true regarding electric circuits?

    <p>They consist of paths for electron flow, creating closed loops</p> Signup and view all the answers

    What is the main application of an ionization chamber?

    <p>Measuring radiation intensity</p> Signup and view all the answers

    What describes the behavior of alternating current (AC)?

    <p>Electrons alternate direction periodically</p> Signup and view all the answers

    What type of readings are available through the use of proportional counters?

    <p>Real-time analysis of radiation types</p> Signup and view all the answers

    What is the primary characteristic of an insulator?

    <p>Extremely high resistance to electron flow</p> Signup and view all the answers

    Which example represents a typical semiconductor material?

    <p>Silicon</p> Signup and view all the answers

    What region lies between visible light and ionizing radiation?

    <p>Radiofrequency Radiation</p> Signup and view all the answers

    What characteristic of photon interaction is highlighted in wave-particle duality?

    <p>Photons interact most easily when matter is similar in size to their wavelength.</p> Signup and view all the answers

    What is the role of attenuation in radiologic science?

    <p>It refers to the scattering and absorption reduction of x-ray intensity.</p> Signup and view all the answers

    What type of electromagnetic radiation is classified as ionizing radiation?

    <p>X-rays and Gamma Rays</p> Signup and view all the answers

    Which statement is true regarding the characteristics of ionizing radiation?

    <p>It is capable of ionization and has higher energy.</p> Signup and view all the answers

    How do microwaves differ from radiofrequency radiation in terms of wavelength?

    <p>Microwaves have shorter wavelengths than radiofrequency.</p> Signup and view all the answers

    What is the significance of the visible light region in radiologic imaging?

    <p>Essential for viewing radiographic and fluoroscopic images.</p> Signup and view all the answers

    Which type of electromagnetic radiation is particularly known for interacting with food during cooking?

    <p>Microwave Radiation</p> Signup and view all the answers

    What characteristic does violet light have in the electromagnetic spectrum?

    <p>Highest frequency and shortest wavelength</p> Signup and view all the answers

    What is the primary effect of refraction when visible light passes between transparent mediums?

    <p>It alters the path of light</p> Signup and view all the answers

    What are the types of invisible light mentioned?

    <p>Infrared and ultraviolet light</p> Signup and view all the answers

    What does the electromagnetic wave equation, $c = fλ$, signify?

    <p>The frequency and wavelength multiply to equal a constant speed of light</p> Signup and view all the answers

    How does infrared light impact substances?

    <p>It produces radiant heat that warms any substance</p> Signup and view all the answers

    What is the definition of acceleration in physics?

    <p>The rate of change of velocity with time</p> Signup and view all the answers

    What is the formula used to calculate weight?

    <p>Wt = m * g</p> Signup and view all the answers

    According to Newton's law of motion, what happens to an object in motion without any external forces?

    <p>It will remain in motion with the same velocity</p> Signup and view all the answers

    Which unit is used to measure force?

    <p>Newton (N)</p> Signup and view all the answers

    What does the term momentum represent in physics?

    <p>The product of mass and velocity</p> Signup and view all the answers

    Which law states that for every action there is an equal and opposite reaction?

    <p>Law of Action/Reaction</p> Signup and view all the answers

    In the context of Newton's laws, what does the equation F = (m)(a) represent?

    <p>The law of force acting on an object</p> Signup and view all the answers

    How is acceleration defined mathematically?

    <p>Acceleration = velocity / time</p> Signup and view all the answers

    What is the primary characteristic of alpha decay?

    <p>Loss of 2 protons and 2 neutrons</p> Signup and view all the answers

    What happens during beta plus decay?

    <p>A positron is released as a result of a proton transforming into a neutron</p> Signup and view all the answers

    What is the effect on the atomic number during electron capture decay?

    <p>It decreases by one</p> Signup and view all the answers

    Which decay mode is characterized by the emission of negaton and anti-neutrino?

    <p>Beta minus decay</p> Signup and view all the answers

    What is the purpose of the concept of half-life in radioactivity?

    <p>To determine the time taken for radioactivity to reduce to half its initial value</p> Signup and view all the answers

    In which decay process does a metastable state occur?

    <p>Gamma decay</p> Signup and view all the answers

    How does beta plus decay affect the mass number?

    <p>It stays the same</p> Signup and view all the answers

    What defines a radionuclide?

    <p>Atoms involved in radioactive decay</p> Signup and view all the answers

    Which type of decay is characterized by the emission of positron decay?

    <p>Beta plus decay</p> Signup and view all the answers

    What is the significance of isobaric transition in radioactive decay?

    <p>It involves a change in atomic number with no change in mass number</p> Signup and view all the answers

    Which type of magnet is categorized as being strongly magnetized?

    <p>Ferromagnetic</p> Signup and view all the answers

    What is the SI unit for measuring magnetic field strength?

    <p>Tesla</p> Signup and view all the answers

    What condition describes materials that are reluctant to lose their magnetism?

    <p>Hysteresis</p> Signup and view all the answers

    In which type of transformer is the primary side characterized by high voltage and low current?

    <p>Step-down transformer</p> Signup and view all the answers

    Which component adjusts voltage to precisely 220V in an x-ray imaging system?

    <p>Line compensator</p> Signup and view all the answers

    What is the primary role of an electric motor in an x-ray system?

    <p>Produce mechanical motion</p> Signup and view all the answers

    Which factor does NOT influence the magnitude of induced current according to Faraday's Law?

    <p>Length of conductor</p> Signup and view all the answers

    What defines a solenoid in the context of electromagnetism?

    <p>A coil of wire</p> Signup and view all the answers

    In transformers, how is the ratio of voltage change related to the number of turns?

    <p>Directly proportional</p> Signup and view all the answers

    Which magnetic state of matter is characterized by weak repulsion?

    <p>Diamagnetic</p> Signup and view all the answers

    What is a primary feature of an electromagnet?

    <p>Ability to adjust magnetic field</p> Signup and view all the answers

    What type of current does a transformer primarily work with?

    <p>Alternating current</p> Signup and view all the answers

    What is the main action of an electric generator?

    <p>Convert mechanical energy to electrical energy</p> Signup and view all the answers

    What is the current recommended weekly whole-body dose limit for radiation exposure?

    <p>1 mSv/week</p> Signup and view all the answers

    What does the collimation test ensure regarding misalignment?

    <p>Must not exceed 2% of the SID</p> Signup and view all the answers

    What is the minimum total filtration required for a radiographic imaging system?

    <p>2.5 mm Al</p> Signup and view all the answers

    Which tool is NOT commonly used for measuring focal spot size?

    <p>Thermal camera</p> Signup and view all the answers

    What is the acceptable accuracy for kVp measurement?

    <p>Within 10% of the indicated kVp</p> Signup and view all the answers

    How often should the central beam alignment be evaluated?

    <p>Once in two months</p> Signup and view all the answers

    What is the purpose of solid state radiation detectors in radiology?

    <p>To measure exposure time accuracy</p> Signup and view all the answers

    What does the term 'focal spot size' refer to in x-ray imaging?

    <p>The spatial resolution of the imaging</p> Signup and view all the answers

    Which dose limit is established for a pregnant radiation worker regarding the fetus?

    <p>5.0 mSv</p> Signup and view all the answers

    What is the maximum acceptable deviation for exposure linearity at adjacent mA stations?

    <p>Within 10%</p> Signup and view all the answers

    How is screen film contact evaluated in radiology?

    <p>By radiographing a wire mesh pattern</p> Signup and view all the answers

    What frequency is suggested for evaluating exposure time accuracy?

    <p>As needed</p> Signup and view all the answers

    Which component is NOT part of the theoretical aspect of information science?

    <p>Gathering data</p> Signup and view all the answers

    What is the maximum misalignment percentage allowed for positive beam limiting collimators?

    <p>2%</p> Signup and view all the answers

    What is the distinguishing characteristic of matter?

    <p>Mass measured in kilograms</p> Signup and view all the answers

    Which form of energy is contained in the nucleus of an atom?

    <p>Nuclear Energy</p> Signup and view all the answers

    What type of radiation is classified as not being ionizing?

    <p>Ultrasound</p> Signup and view all the answers

    What kind of energy is associated with the motion of an atom or molecule?

    <p>Thermal Energy</p> Signup and view all the answers

    Which term describes the transfer of energy through electromagnetic radiation?

    <p>Radiation</p> Signup and view all the answers

    What does Coulomb's law describe regarding charged particles?

    <p>The force is inversely proportional to the square of the distance between them.</p> Signup and view all the answers

    Which statement correctly reflects the Law of Conservation of Energy?

    <p>Energy can change forms but cannot be created or destroyed.</p> Signup and view all the answers

    At what speed do electromagnetic waves travel?

    <p>3 × 10^8 m/s</p> Signup and view all the answers

    What range does the frequency of electromagnetic radiation typically fall within?

    <p>10^18 - 10^22 Hz</p> Signup and view all the answers

    What does the electric field cause charged particles to do?

    <p>Move from one pole to another.</p> Signup and view all the answers

    In the context of electricity, what happens to uncharged particles in an electric field?

    <p>They do not interact with the electric field.</p> Signup and view all the answers

    Which of the following materials is considered conductive?

    <p>Silicon</p> Signup and view all the answers

    What is a key characteristic of unlike charges in proximity?

    <p>They attract each other.</p> Signup and view all the answers

    What is the primary characteristic of a photon?

    <p>It is a small bundle of electromagnetic energy.</p> Signup and view all the answers

    How is frequency related to energy in a photon?

    <p>Frequency is directly proportional to energy.</p> Signup and view all the answers

    What is the SI unit for measuring frequency?

    <p>Hertz</p> Signup and view all the answers

    What does the wavelength represent in a sine wave?

    <p>The distance from one crest to the next crest</p> Signup and view all the answers

    What is the relationship between wavelength and frequency?

    <p>Wavelength is inversely proportional to frequency.</p> Signup and view all the answers

    In the context of electromagnetic waves, which region is essential for producing high-quality radiographs?

    <p>X-ray Region</p> Signup and view all the answers

    What is the significance of using the Greek symbol λ in wave equations?

    <p>It represents wavelength.</p> Signup and view all the answers

    What describes the behavior of ultrasound waves compared to electromagnetic waves?

    <p>They require matter to propagate.</p> Signup and view all the answers

    Which color of visible light has the longest wavelength?

    <p>Red</p> Signup and view all the answers

    What does the wave equation apply to in terms of energy types?

    <p>Both sound and electromagnetic energy</p> Signup and view all the answers

    What is the main feature of alpha decay?

    <p>Decrease in atomic mass by 4</p> Signup and view all the answers

    What happens to the atomic number during beta plus decay?

    <p>It increases by 1</p> Signup and view all the answers

    What characterizes gamma decay?

    <p>It releases excess energy in the form of gamma rays</p> Signup and view all the answers

    During electron capture, what is the result of the proton being converted?

    <p>The atomic number decreases by 1</p> Signup and view all the answers

    What is the definition of half-life in radioactive decay?

    <p>The time required for a quantity to reduce to one-half</p> Signup and view all the answers

    Which decay mode is characterized by the emission of a negatron?

    <p>Beta minus decay</p> Signup and view all the answers

    What type of transition occurs during isobaric transitions?

    <p>No change in total nucleon number</p> Signup and view all the answers

    Which of the following statements is true regarding beta plus decay?

    <p>Results in no change in mass number</p> Signup and view all the answers

    What is a characteristic feature of radionuclides?

    <p>Undergoes radioactive decay</p> Signup and view all the answers

    What results from radioactive disintegration?

    <p>Formation of a different element</p> Signup and view all the answers

    What does magnetic susceptibility indicate about a material?

    <p>The degree to which it can be magnetized</p> Signup and view all the answers

    Which type of magnet is significantly magnetized by external forces?

    <p>Ferromagnetic</p> Signup and view all the answers

    What occurs in hysteresis in magnetic materials?

    <p>Some materials retain magnetism even after the field is removed</p> Signup and view all the answers

    Which transformer type has a turns ratio greater than 1?

    <p>Step-up transformer</p> Signup and view all the answers

    Michael Faraday's Law of Electromagnetic Induction emphasizes which of the following?

    <p>The induction of current from a changing magnetic field</p> Signup and view all the answers

    Which of the following is a key characteristic of an electromagnet?

    <p>Its magnetic field can be adjusted or turned off</p> Signup and view all the answers

    What defines a closed-core transformer?

    <p>It minimizes energy losses due to eddy currents</p> Signup and view all the answers

    In the context of electromagnetic devices, what happens in an electric motor?

    <p>Electric current produces mechanical motion</p> Signup and view all the answers

    What is the primary purpose of a line compensator in x-ray systems?

    <p>To adjust voltage to precise levels</p> Signup and view all the answers

    Which of the following is not a function of transformers?

    <p>Amplifying current</p> Signup and view all the answers

    What characteristic does a shell-type transformer enhance?

    <p>Confines magnetic field lines more efficiently</p> Signup and view all the answers

    Which material is classified as weakly attracted to magnets?

    <p>Gadolinium</p> Signup and view all the answers

    How does the relationship between voltage and current behave in transformers according to transformer law?

    <p>Increase in voltage results in a decrease in current</p> Signup and view all the answers

    What represents the relationship between force, distance, and work?

    <p>W = (F)(d)</p> Signup and view all the answers

    Which quantity describes the rate of doing work?

    <p>Power</p> Signup and view all the answers

    Which statement best describes kinetic energy?

    <p>Energy due to the random motion of molecules</p> Signup and view all the answers

    In what method is heat primarily transferred through material by touching?

    <p>Conduction</p> Signup and view all the answers

    What does the symbol 'p' represent?

    <p>Momentum</p> Signup and view all the answers

    What does the term ALARA stand for in radiation protection?

    <p>As Low As Reasonably Achievable</p> Signup and view all the answers

    Which principle of radiation protection is NOT one of the main cardinal principles?

    <p>Dose</p> Signup and view all the answers

    What is the primary purpose of using collimation in radiography?

    <p>To improve image contrast</p> Signup and view all the answers

    Which type of shielding is specifically recommended for individuals of childbearing age?

    <p>Gonadal shielding</p> Signup and view all the answers

    What is the unit of mass in the metric system?

    <p>Kilogram</p> Signup and view all the answers

    Which of the following statements about filtration in radiography is true?

    <p>Filtration decreases patient dose by absorbing low energy x-rays</p> Signup and view all the answers

    What is the SI unit of current?

    <p>Ampere</p> Signup and view all the answers

    What is the speed of an object measured in SI units called?

    <p>Velocity</p> Signup and view all the answers

    What is the speed of light in meters per second?

    <p>3x10^8 m/s</p> Signup and view all the answers

    Which type of radiation is classified as nonionizing?

    <p>Ultrasound (UTZ)</p> Signup and view all the answers

    What are the three wave parameters of electromagnetic radiation?

    <p>Amplitude, Velocity, Frequency</p> Signup and view all the answers

    What effect does increased amplitude have on electromagnetic radiation?

    <p>Increases the intensity of the wave</p> Signup and view all the answers

    What significant property of visible light was demonstrated by James Clerk Maxwell?

    <p>It has both electrical and magnetic properties</p> Signup and view all the answers

    What does the alpha decay process result in?

    <p>Loss of 2 protons and 2 neutrons</p> Signup and view all the answers

    Which of the following statements about isobaric processes is correct?

    <p>They maintain constant atomic number while changing neutron count</p> Signup and view all the answers

    Which type of radiation is NOT capable of removing or ejecting an outer shell electron?

    <p>Nonionizing radiation</p> Signup and view all the answers

    What is the SI unit for frequency?

    <p>hertz (Hz)</p> Signup and view all the answers

    How is the energy of a photon related to its frequency?

    <p>Directly proportional</p> Signup and view all the answers

    What does the Greek symbol λ (lambda) represent in wave theory?

    <p>Wavelength</p> Signup and view all the answers

    What is true about the movement of a photon?

    <p>It always travels at the speed of light.</p> Signup and view all the answers

    What characterizes a sine wave?

    <p>It oscillates in a smooth, periodic manner.</p> Signup and view all the answers

    Which statement is true about visible light?

    <p>It interacts with the rods and cones of the eye.</p> Signup and view all the answers

    What is the relationship between frequency and wavelength?

    <p>Inversely proportional</p> Signup and view all the answers

    At what rate does 1 hertz equal?

    <p>1 cycle every second</p> Signup and view all the answers

    In which region are radio frequency waves primarily used?

    <p>Magnetic Resonance Imaging</p> Signup and view all the answers

    What aspect is fundamental to achieving a high-quality radiograph?

    <p>X-ray region</p> Signup and view all the answers

    What does the annual whole-body dose limit recommended by the International Commission on Radiological Protection (ICRP) currently stand at?

    <p>20 mSv</p> Signup and view all the answers

    Which of the following statements about filtration in radiography is correct?

    <p>The minimum total filtration required is 2.5 mm Al.</p> Signup and view all the answers

    What is the purpose of positive beam-limiting (PBL) collimators?

    <p>To adjust collimating shutters based on the size of the image receptor.</p> Signup and view all the answers

    For a pregnant radiology technologist, what is the dose limit for the fetus?

    <p>5 mSv</p> Signup and view all the answers

    Which tool is NOT used to measure focal spot size?

    <p>Radiographic film</p> Signup and view all the answers

    How often should kVp calibration be evaluated?

    <p>Once a year</p> Signup and view all the answers

    What is the acceptable accuracy percentage for exposure times less than 10 ms?

    <p>20%</p> Signup and view all the answers

    Which frequency is appropriate for evaluating output, measured in mR/mAs?

    <p>Once a month</p> Signup and view all the answers

    What does screen-film contact evaluation assess?

    <p>Clarity and sharpness of images</p> Signup and view all the answers

    What must the misalignment in the collimation test not exceed?

    <p>2% of the SID</p> Signup and view all the answers

    What is the primary goal of quality assurance in radiology?

    <p>To monitor proper patient scheduling and image interpretation.</p> Signup and view all the answers

    What does exposure linearity test evaluate?

    <p>Consistency across different exposure times.</p> Signup and view all the answers

    In the evaluation of focal spot size, what tool is primarily used to determine limiting spatial frequency?

    <p>Star pattern</p> Signup and view all the answers

    Which term describes the interdisciplinary field focused on the analysis, classification, and retrieval of information?

    <p>Information Science</p> Signup and view all the answers

    What does the symbol 'p' represent in physics?

    <p>Momentum</p> Signup and view all the answers

    What is the SI unit for expressing power?

    <p>Watt</p> Signup and view all the answers

    Which equation accurately represents the calculation of work?

    <p>W = F * d</p> Signup and view all the answers

    What type of heat transfer occurs through the direct contact of materials?

    <p>Conduction</p> Signup and view all the answers

    Which of the following best describes the concept of thermal radiation?

    <p>Transfer of heat in the form of electromagnetic waves</p> Signup and view all the answers

    What is the defining characteristic of matter?

    <p>Mass measured in kilograms</p> Signup and view all the answers

    Which type of energy is associated with the nucleus of an atom?

    <p>Nuclear Energy</p> Signup and view all the answers

    What form of radiation is ultrasound considered?

    <p>Non-ionizing radiation</p> Signup and view all the answers

    What does thermal energy primarily relate to?

    <p>Energy in the atomic and molecular motion</p> Signup and view all the answers

    How is electromagnetic radiation characterized?

    <p>A transfer of energy</p> Signup and view all the answers

    What does the atomic mass number signify in an atom?

    <p>Total number of protons plus neutrons</p> Signup and view all the answers

    What determines the chemical element of an atom?

    <p>Number of protons in the nucleus</p> Signup and view all the answers

    Which principle explains why no outer shell can contain more than 8 electrons?

    <p>Octet Rule</p> Signup and view all the answers

    Which pair of isotopes shares the same number of protons?

    <p>Isotopes</p> Signup and view all the answers

    What is the relationship between the principal quantum number and the periodic table?

    <p>It corresponds to the period of the element</p> Signup and view all the answers

    What type of bond is characterized by the sharing of electrons?

    <p>Covalent bonds</p> Signup and view all the answers

    What does the formula $2n^2$ represent in atomic structure?

    <p>Maximum electrons per shell</p> Signup and view all the answers

    Which term refers to the center-seeking force that keeps an electron in orbit?

    <p>Centripetal force</p> Signup and view all the answers

    What is the relationship between frequency and photon energy?

    <p>They are directly proportional</p> Signup and view all the answers

    What does the symbol $ u$ represent in wave physics?

    <p>Frequency</p> Signup and view all the answers

    How is wavelength ($ ext{λ}$) defined in terms of a sine wave?

    <p>Distance from one crest to another</p> Signup and view all the answers

    What is the SI unit for measuring frequency?

    <p>Hertz (Hz)</p> Signup and view all the answers

    What defines a photon in terms of mass and charge?

    <p>No mass and no charge</p> Signup and view all the answers

    What describes the relationship between wavelength and frequency?

    <p>Inversely proportional</p> Signup and view all the answers

    Which region of the electromagnetic spectrum is essential for producing high-quality radiographs?

    <p>X-ray region</p> Signup and view all the answers

    At what speed do photons travel through space?

    <p>3 × 10^8 m/s</p> Signup and view all the answers

    What is the term used to describe the wave of moving molecules requiring matter?

    <p>Ultrasound wave</p> Signup and view all the answers

    Which color of visible light has the longest wavelength?

    <p>Red</p> Signup and view all the answers

    What is the primary process involved in beta plus decay?

    <p>A proton is converted into a neutron.</p> Signup and view all the answers

    Which type of decay emits the most ionizing and destructive particles?

    <p>Alpha decay</p> Signup and view all the answers

    What does the half-life of a radioactive substance represent?

    <p>The time required for radioactivity to reduce by one-half.</p> Signup and view all the answers

    During gamma decay, what happens to the atomic number of the nucleus?

    <p>It remains unchanged.</p> Signup and view all the answers

    What describes nuclear radioactivity?

    <p>Emission of particles and energy in order to become stable.</p> Signup and view all the answers

    What occurs in electron capture decay?

    <p>A proton is converted into a neutron.</p> Signup and view all the answers

    How is the radioactive decay formula expressed?

    <p>Remaining = (Original value/activity)(0.5)n</p> Signup and view all the answers

    Which type of decay is characterized by the emission of a positron?

    <p>Beta plus decay</p> Signup and view all the answers

    What is produced during alpha decay?

    <p>Alpha particles consisting of 2 protons and 2 neutrons.</p> Signup and view all the answers

    In the context of radioactivity, what is an isobaric transition?

    <p>Transformation with conservation of nucleon number.</p> Signup and view all the answers

    What is the distinguishing characteristic of matter?

    <p>Mass measured in kilograms</p> Signup and view all the answers

    Which type of energy is contained within the nucleus of an atom?

    <p>Nuclear Energy</p> Signup and view all the answers

    What is thermal energy primarily concerned with?

    <p>Energy at the atomic and molecular level</p> Signup and view all the answers

    Which of the following statements is true about radiation?

    <p>Ultrasound is a form of radiation but is not ionizing</p> Signup and view all the answers

    What is measured when an electron moves through an electrical potential difference?

    <p>Electrical Energy</p> Signup and view all the answers

    What is the relationship between photon energy and frequency?

    <p>They are directly proportional.</p> Signup and view all the answers

    What does the symbol λ (lambda) represent in wave terminology?

    <p>The wavelength of the wave.</p> Signup and view all the answers

    At what rate does a photon travel through space?

    <p>3 × 10^8 m/s</p> Signup and view all the answers

    What unit is used to express frequency?

    <p>Hertz (Hz)</p> Signup and view all the answers

    Which of the following statements about sound and electromagnetic waves is accurate?

    <p>Both are represented by a sinusoidal waveform.</p> Signup and view all the answers

    How is wavelength related to frequency according to wave principles?

    <p>Wavelength is inversely proportional to frequency.</p> Signup and view all the answers

    Visible light is often measured in which of the following units?

    <p>Nanometers (nm)</p> Signup and view all the answers

    What is the significance of the frequency in producing X-rays?

    <p>It determines the energy and penetration of the X-rays.</p> Signup and view all the answers

    In the context of sound waves, what is meant by ultrasound?

    <p>It involves the movement of molecules and requires matter.</p> Signup and view all the answers

    What is the SI unit of frequency?

    <p>Hertz (Hz)</p> Signup and view all the answers

    What is defined as the ability to do work?

    <p>Energy</p> Signup and view all the answers

    What does Newton's law of motion state about a body at rest?

    <p>It will remain at rest unless acted upon by a force.</p> Signup and view all the answers

    What is the formula for calculating weight?

    <p>Wt = m * g</p> Signup and view all the answers

    Which of the following statements accurately describes momentum?

    <p>It is the product of mass and velocity.</p> Signup and view all the answers

    According to Newton's law of force, what is the relationship between force, mass, and acceleration?

    <p>Force is equal to mass multiplied by acceleration.</p> Signup and view all the answers

    What best characterizes the law of action/reaction?

    <p>For every action, there is an equal and opposite action.</p> Signup and view all the answers

    What is the correct unit for measuring force?

    <p>Newton (N)</p> Signup and view all the answers

    How is acceleration defined in terms of velocity and time?

    <p>Acceleration is velocity divided by time.</p> Signup and view all the answers

    What effect does an increase in distance from the radiation source have on radiographic density?

    <p>Density decreases to less than half</p> Signup and view all the answers

    Which property is true regarding x-rays in terms of their interaction with tissues?

    <p>They appear white in radiographs</p> Signup and view all the answers

    What distinguishes gamma rays from x-rays in their origin?

    <p>Gamma rays originate from radioactive decay</p> Signup and view all the answers

    What is Max Planck known for in the context of electromagnetic radiation?

    <p>Synthesizing the understanding of electromagnetic radiation</p> Signup and view all the answers

    Which statement best describes the inverse square law?

    <p>Increasing distance reduces intensity exponentially</p> Signup and view all the answers

    What does radiolucent mean in imaging?

    <p>Transmits x-rays and appears black</p> Signup and view all the answers

    What occurs when like charges are brought near each other?

    <p>They repel</p> Signup and view all the answers

    What is a characteristic of x-rays as described in the context of their properties?

    <p>They are a form of ionizing radiation</p> Signup and view all the answers

    In the context of electric potential, what is the SI unit?

    <p>Volt (V)</p> Signup and view all the answers

    How does the density of a radiograph change when the source-to-image distance is doubled?

    <p>Density is reduced to one-fourth</p> Signup and view all the answers

    What is the approximate threshold dose for hematologic depression?

    <p>25 rad</p> Signup and view all the answers

    At what radiation dose is epilation likely to occur?

    <p>300 rad</p> Signup and view all the answers

    What syndrome is characterized by electrolyte imbalance, fatigue, and shock after radiation exposure?

    <p>Gastrointestinal Death</p> Signup and view all the answers

    What percentage of irradiated subjects is expected to die within 60 days at the LD 50/60 level?

    <p>50%</p> Signup and view all the answers

    What is the mean survival time for patients experiencing acute radiation syndrome?

    <p>0-3 days</p> Signup and view all the answers

    Which clinical symptom is NOT associated with hematologic syndrome?

    <p>Seizures</p> Signup and view all the answers

    What is the primary cause of CNS death following radiation exposure?

    <p>Increased fluid content in the brain</p> Signup and view all the answers

    At what dose is skin erythema likely to manifest?

    <p>200 rad</p> Signup and view all the answers

    What is the minimum dose that leads to a significant increase in genetic mutations?

    <p>25 rad</p> Signup and view all the answers

    Which of the following clinical symptoms is associated with the gastrointestinal period of radiation exposure?

    <p>Severe diarrhea</p> Signup and view all the answers

    Which dose level is associated with temporary infertility in males due to radiation exposure?

    <p>200 rad</p> Signup and view all the answers

    During which period do severe symptoms typically reappear after a radiation exposure?

    <p>Manifest Illness Period</p> Signup and view all the answers

    What does the term 'prodomal' refer to in acute radiation syndrome?

    <p>Early symptoms following exposure</p> Signup and view all the answers

    What rate of chromosome aberration is expected at a dose of 5 rad?

    <p>Minimal</p> Signup and view all the answers

    What is the distinguishing characteristic of matter?

    <p>Mass measured in kilograms</p> Signup and view all the answers

    Which type of energy is contained in the nucleus of an atom?

    <p>Nuclear Energy</p> Signup and view all the answers

    What is the correct term for the energy of motion at the atomic and molecular level?

    <p>Thermal Energy</p> Signup and view all the answers

    Which of the following correctly describes electromagnetic radiation?

    <p>It is a transfer of energy without the need for a medium</p> Signup and view all the answers

    What does an electron do to produce electrical energy?

    <p>Moves through an electrical potential difference</p> Signup and view all the answers

    In a series circuit, how are the circuit elements connected?

    <p>All are connected in a line along the same conductor</p> Signup and view all the answers

    What happens to the current in a parallel circuit?

    <p>The sum of the currents through each element equals the total circuit current</p> Signup and view all the answers

    What is the relationship between voltage and current in a series circuit?

    <p>The total voltage is equal to the sum of individual voltage drops</p> Signup and view all the answers

    How is total resistance calculated in a parallel circuit?

    <p>The inverse of the sum of the reciprocals of each resistance</p> Signup and view all the answers

    What characteristic describes the voltage across each element in a parallel circuit?

    <p>It is the same and equals the total circuit voltage</p> Signup and view all the answers

    Which invention is associated with H.C. Snook in 1907?

    <p>Interrupter less transformer</p> Signup and view all the answers

    What was the function of Barium Platinocyanide in Roentgen's experiments?

    <p>As a fluorescent material</p> Signup and view all the answers

    During which decade did MRI become an accepted modality in medical imaging?

    <p>1980s</p> Signup and view all the answers

    What type of images does a fluoroscopy system provide?

    <p>Dynamic images</p> Signup and view all the answers

    Which inventor demonstrated the first application of collimation and filtration in the early 1900s?

    <p>William Rollins</p> Signup and view all the answers

    In 1946, what technology was demonstrated at Bell Telephone Laboratories?

    <p>Light amplifier</p> Signup and view all the answers

    What is the primary measurement of X-ray voltage typically measured in?

    <p>kVp</p> Signup and view all the answers

    What is the significance of the Potter Bucky grid introduced in 1921?

    <p>It allows for moving grids</p> Signup and view all the answers

    Which of the following quantities is classified as a secondary quantity?

    <p>Radioactivity</p> Signup and view all the answers

    What advancement did Gustav Bucky contribute to the field of X-ray imaging?

    <p>Stationary grid</p> Signup and view all the answers

    What is a key characteristic of superconductors?

    <p>They allow electrons to flow without any resistance.</p> Signup and view all the answers

    Which of the following is NOT a property of an insulator?

    <p>Allows electrons to flow easily.</p> Signup and view all the answers

    What does Ohm's Law define in relation to an electric circuit?

    <p>Voltage is equal to the product of current and resistance.</p> Signup and view all the answers

    What is the primary function of conductors in an electric circuit?

    <p>To allow electrons to flow with minimal resistance.</p> Signup and view all the answers

    In what scenario would a semiconductor behave like an insulator?

    <p>At extremely low temperatures.</p> Signup and view all the answers

    What does an electric circuit describe?

    <p>The complete path of electron flow through components.</p> Signup and view all the answers

    Which of the following statements about electric resistance is true?

    <p>Increasing resistance results in reduced electric current.</p> Signup and view all the answers

    What occurs during alternating current operation?

    <p>Electrons change direction in a sinusoidal wave.</p> Signup and view all the answers

    What is true about the magnetic field?

    <p>It is generated by any charged particle in motion.</p> Signup and view all the answers

    What is a unique characteristic of superconductors compared to conventional conductors?

    <p>They exhibit zero resistance below a critical temperature.</p> Signup and view all the answers

    What is the approximate threshold dose for Hematologic Depression?

    <p>25 rad</p> Signup and view all the answers

    Which clinical symptom is associated with Acute Radiation Syndrome?

    <p>Fatigue</p> Signup and view all the answers

    What does the acronym LD 50/60 refer to in radiation exposure?

    <p>Dose leading to 50% mortality in 60 days</p> Signup and view all the answers

    What is a common consequence of Gonadal Dysfunction at 500 rad?

    <p>Permanent sterility</p> Signup and view all the answers

    What is the mean survival time for a person exposed to greater than 5000 rad?

    <p>0-3 days</p> Signup and view all the answers

    Which type of tissue damage is characterized by lack of function or shrinkage?

    <p>Local tissue damage</p> Signup and view all the answers

    What is the clinical symptom of skin erythema at 200 rad?

    <p>Reddish skin appearance</p> Signup and view all the answers

    What does a dose of 1000-5000 rad primarily affect?

    <p>Gastrointestinal (GI) death</p> Signup and view all the answers

    Which syndrome is characterized by a mean survival time of 10-60 days?

    <p>Hematologic syndrome</p> Signup and view all the answers

    What radiation dose is required to observe acute radiation syndrome symptoms?

    <p>100 rad</p> Signup and view all the answers

    What is the likely cause of death following elevated intracranial pressure from radiation exposure?

    <p>Vasculitis</p> Signup and view all the answers

    What does the term 'Prodromal Period' refer to in radiation contexts?

    <p>First signs of sickness following exposure</p> Signup and view all the answers

    Which of the following effects is primarily associated with chromosome aberration?

    <p>Long-term genetic impact</p> Signup and view all the answers

    What is a symptom of the gastrointestinal period after high radiation exposure?

    <p>Severe nausea and diarrhea</p> Signup and view all the answers

    What is the half value layer (HVL) in radiation physics?

    <p>The thickness of absorber necessary to reduce radiation intensity to half</p> Signup and view all the answers

    What does ALARA stand for in health physics?

    <p>As Low As Reasonably Achievable</p> Signup and view all the answers

    Which organization conducts research and provides recommendations on radiation protection worldwide?

    <p>ICRP</p> Signup and view all the answers

    How does increasing the distance between a radiation source and a person affect radiation exposure?

    <p>Radiation exposure decreases rapidly</p> Signup and view all the answers

    Who was the first American fatality attributed to radiation exposure?

    <p>Clarence Dally</p> Signup and view all the answers

    What is defined as the ability to do work?

    <p>Energy</p> Signup and view all the answers

    Which type of radiation is known to cause ionization by removing electrons from atoms?

    <p>Gamma radiation</p> Signup and view all the answers

    What is the primary use of a Geiger-Muller counter in nuclear medicine laboratories?

    <p>Surveying for low radiation levels and contamination</p> Signup and view all the answers

    Which statement describes the law of conservation of energy?

    <p>Energy may be transformed but cannot be created or destroyed.</p> Signup and view all the answers

    Which quantity corresponds to the customary unit 'Rad' in the context of radiation exposure?

    <p>Absorbed Dose</p> Signup and view all the answers

    What is the largest source of man-made radiation exposure?

    <p>Diagnostic X-rays</p> Signup and view all the answers

    What is the primary focus of quality control in imaging systems for radiologists?

    <p>Providing optimal image quality</p> Signup and view all the answers

    What is the function of preventive maintenance in nuclear medicine equipment?

    <p>Routine procedures performed to ensure proper functioning</p> Signup and view all the answers

    What process refers to the acquisition of a positive or negative charge by an atom or molecule?

    <p>Ionization</p> Signup and view all the answers

    Which type of energy is the energy of motion?

    <p>Kinetic energy</p> Signup and view all the answers

    Which is true about the unit 'Sievert' in radiation measurement?

    <p>It is the SI unit for effective dose</p> Signup and view all the answers

    Which year did Wilhelm Roentgen accidentally discover X-rays?

    <p>1895</p> Signup and view all the answers

    Which natural source contributes the largest amount of ionizing radiation exposure?

    <p>Radon</p> Signup and view all the answers

    What is the unit used to measure energy in radiology?

    <p>Electron volt</p> Signup and view all the answers

    Which type of radiation is primarily emitted by the sun and stars?

    <p>Cosmic radiation</p> Signup and view all the answers

    What is the primary result of beta plus decay?

    <p>Conversion of a proton into a neutron</p> Signup and view all the answers

    Which decay mode results in a decrease in atomic number by 1?

    <p>Electron capture</p> Signup and view all the answers

    Which of the following best describes alpha decay?

    <p>Loss of 2 protons and 2 neutrons</p> Signup and view all the answers

    What does the term 'half-life' refer to in radioactivity?

    <p>Time required to reduce radioactivity to half its original value</p> Signup and view all the answers

    What is produced during gamma decay?

    <p>Gamma rays</p> Signup and view all the answers

    Which decay mode involves the nucleus emitting a positron?

    <p>Beta plus decay</p> Signup and view all the answers

    In the context of radioactivity, what does an isobaric transition indicate?

    <p>No change in atomic number</p> Signup and view all the answers

    Which of the following correctly describes beta minus decay?

    <p>Conversion of a neutron into a proton</p> Signup and view all the answers

    What does the formula for calculating remaining radioactive quantity represent?

    <p>Initial value diminished by half-lives</p> Signup and view all the answers

    Which type of decay involves the conversion of energy without a change in atomic number?

    <p>Gamma decay</p> Signup and view all the answers

    What is the annual effective dose limit for occupational exposure?

    <p>50 mSv</p> Signup and view all the answers

    What is the cumulative effective dose (CEfD) formula based on age?

    <p>Age x 10 mSv</p> Signup and view all the answers

    At what exposure rate should the outer boundary be established?

    <p>100 uGya/hr</p> Signup and view all the answers

    What does the Optically Stimulated Luminescence (OSL) monitor primarily measure?

    <p>Radiation exposure</p> Signup and view all the answers

    What is the effective dose to the lens of the eye limit in mSv?

    <p>150 mSv</p> Signup and view all the answers

    Which material is used in OSL dosimeters for radiation detection?

    <p>Aluminum Oxide (Al2O3)</p> Signup and view all the answers

    What is the maximum exposure level that radiation detection apparatus should be capable of measuring?

    <p>500 mGya/hr</p> Signup and view all the answers

    What is the effective dose limit for skin, hands, and feet?

    <p>500 mSv</p> Signup and view all the answers

    What principle focuses on minimizing radiation exposure by optimizing shielding, reducing time, and increasing distance?

    <p>ALARA</p> Signup and view all the answers

    What is the primary measure of distance in radiation protection that refers to the distance traveled by light?

    <p>1 meter</p> Signup and view all the answers

    Which material is emphasized for use in protective apparel to shield against radiation?

    <p>Lead-Impregnated Material</p> Signup and view all the answers

    What does collimation primarily improve in radiation imaging?

    <p>Image contrast</p> Signup and view all the answers

    What quantity does filtration absorb from radiation exposure?

    <p>Low-energy x-rays</p> Signup and view all the answers

    In the context of average velocity, what is the SI unit of measurement?

    <p>meters/second</p> Signup and view all the answers

    What does gonadal shielding specifically protect against?

    <p>Radiation exposure for persons of childbearing age</p> Signup and view all the answers

    What defines an intensifying screen in radiography?

    <p>Reduces x-ray exposure by more than 95%</p> Signup and view all the answers

    What is the unit of measurement for work?

    <p>Joule (J)</p> Signup and view all the answers

    Which equation correctly represents the relationship between work, force, and distance?

    <p>$W = F(d)$</p> Signup and view all the answers

    Which statement describes power in the context of work?

    <p>Power is the rate at which work is performed.</p> Signup and view all the answers

    In the context of thermal energy, what is convection primarily concerned with?

    <p>Mechanical transfer of heat in fluids</p> Signup and view all the answers

    How is momentum represented in physics?

    <p>p</p> Signup and view all the answers

    What does the formula $Wt = (m)(g)$ represent?

    <p>The relationship between weight and mass</p> Signup and view all the answers

    What is the unit of measurement for force as per Newton's Law of Motion?

    <p>Newton (N)</p> Signup and view all the answers

    According to Newton's Law of Inertia, what will a body do when no external force acts on it?

    <p>It will remain at rest or continue to move</p> Signup and view all the answers

    Which of the following correctly defines acceleration?

    <p>The change in velocity over time</p> Signup and view all the answers

    What is the product of mass and velocity known as?

    <p>Momentum</p> Signup and view all the answers

    What does Newton's Law of Action/Reaction state?

    <p>Every action has an equal and opposite reaction</p> Signup and view all the answers

    Which of the following statements is true regarding energy?

    <p>It can only be transformed, not created or destroyed</p> Signup and view all the answers

    What does the equation $F = (m)(a)$ represent in physics?

    <p>The definition of force acting on an object</p> Signup and view all the answers

    What is the relationship between photon energy and frequency?

    <p>They are directly proportional.</p> Signup and view all the answers

    How is frequency symbolized in physics?

    <p>f</p> Signup and view all the answers

    What does the term wavelength refer to?

    <p>The distance from crest to crest.</p> Signup and view all the answers

    Which of the following units is used to measure frequency?

    <p>Hertz</p> Signup and view all the answers

    In what manner do electromagnetic waves, such as photons, travel?

    <p>At the speed of light.</p> Signup and view all the answers

    What happens to the frequency when the wavelength of a wave increases?

    <p>The frequency decreases.</p> Signup and view all the answers

    What does 'quantum' refer to in the context of photons?

    <p>The smallest quantity of electromagnetic energy.</p> Signup and view all the answers

    What type of wave requires matter for its transmission?

    <p>Ultrasound wave</p> Signup and view all the answers

    Which color of visible light has the longest wavelength?

    <p>Red</p> Signup and view all the answers

    What is the significance of the sinusoidal waveform in electromagnetic energy?

    <p>It describes the shape of the wave.</p> Signup and view all the answers

    What defines a superconductor?

    <p>A material that exhibits no resistance below a critical temperature.</p> Signup and view all the answers

    What is a characteristic of conductors?

    <p>They require voltage to enable the flow of electrons.</p> Signup and view all the answers

    Which of the following materials is considered an insulator?

    <p>Glass</p> Signup and view all the answers

    Electrons in an alternating current flow:

    <p>In a sinusoidal wave pattern alternating directions.</p> Signup and view all the answers

    How is electric current measured?

    <p>In Amperes</p> Signup and view all the answers

    Which of the following statements about semiconductors is true?

    <p>They can behave as insulators or conductors depending on the conditions.</p> Signup and view all the answers

    According to Ohm's Law, the relationship between voltage, current, and resistance is summarized by which formula?

    <p>Voltage = Current x Resistance</p> Signup and view all the answers

    What is a common characteristic of superconductivity?

    <p>No electric potential is needed to enable flow.</p> Signup and view all the answers

    A magnetic field is created by:

    <p>A charged particle in motion.</p> Signup and view all the answers

    What is the primary role of insulators in electric circuits?

    <p>To prevent short circuits and protect from electrocution.</p> Signup and view all the answers

    What does acceleration measure in terms of motion?

    <p>The change in velocity over time</p> Signup and view all the answers

    Which law of motion states that a body will remain at rest unless acted upon by an external force?

    <p>Law of Inertia</p> Signup and view all the answers

    What is the unit of force as described in the content?

    <p>Newton (N)</p> Signup and view all the answers

    How is momentum defined mathematically?

    <p>The product of mass and velocity</p> Signup and view all the answers

    Which equation represents weight in relation to mass and gravity?

    <p>Wt = mg</p> Signup and view all the answers

    What does Newton's Second Law of Motion explain?

    <p>Force is directly proportional to mass and acceleration</p> Signup and view all the answers

    What can be concluded about the conservation of energy?

    <p>Energy can be transformed but not created or destroyed</p> Signup and view all the answers

    Which of the following statements best describes the Law of Action/Reaction?

    <p>For every action, there is an equal and opposite reaction</p> Signup and view all the answers

    What is the primary function of the Crookes tube in early radiography?

    <p>To generate fixed images using X-ray film</p> Signup and view all the answers

    Which invention is associated with H.C. Snook in the context of X-ray technology?

    <p>Interrupter less transformer</p> Signup and view all the answers

    What role does Barium Platinocyanide play in X-ray technology?

    <p>It is used to convert X-rays into visible light</p> Signup and view all the answers

    What advancement was made in 1946 regarding fluoroscopy?

    <p>Demonstration of the light amplifier</p> Signup and view all the answers

    What major innovation did William Coolidge introduce in 1913?

    <p>The coolidge X-ray tube</p> Signup and view all the answers

    Which term refers to the emission of visible light during stimulation?

    <p>Fluorescence</p> Signup and view all the answers

    Which year saw the development of PET and CT technologies?

    <p>1970</p> Signup and view all the answers

    What is measured in kVp in the context of X-ray examinations?

    <p>X-ray quality</p> Signup and view all the answers

    What does the term radiography specifically refer to in medical imaging?

    <p>The process of creating fixed images using X-ray film</p> Signup and view all the answers

    What is the function of a moving grid introduced by Hollis Potter?

    <p>To reduce scatter radiation</p> Signup and view all the answers

    What is the annual effective dose limit for occupational exposure?

    <p>50 mSv</p> Signup and view all the answers

    What is the cumulative effective dose (CEfD) formula based on age?

    <p>Age x 10 mSv</p> Signup and view all the answers

    Which monitoring device uses aluminum oxide chips to measure radiation exposure?

    <p>Optically Stimulated Luminescence (OSL)</p> Signup and view all the answers

    At what exposure rate is the inner boundary for radiation established?

    <p>100 mGya/hr</p> Signup and view all the answers

    What is the effective dose limit for the lens of the eye during occupational exposure?

    <p>150 mSv</p> Signup and view all the answers

    What is the maximum radiation exposure level that detection apparatus should measure?

    <p>500 mGya/hr</p> Signup and view all the answers

    What amount of blue light emitted from Al2O3 chips correlates to 5 mrem of radiation exposure?

    <p>450 nm</p> Signup and view all the answers

    What characterizes gamma rays in terms of their origin?

    <p>They come from inside the nucleus of a radioactive atom.</p> Signup and view all the answers

    What happens to the density of a radiograph when the source-to-image distance (SID) is doubled?

    <p>Density is reduced to 1/4.</p> Signup and view all the answers

    Which of the following best describes X-rays?

    <p>They are polyenergetic and behave like particles.</p> Signup and view all the answers

    What principle states that the intensity of radiation is inversely proportional to the square of the distance from the source?

    <p>Inverse Square Law.</p> Signup and view all the answers

    What is the primary distinction between radiolucent and radiopaque materials in radiography?

    <p>Radiolucent materials permit the transmission of X-rays.</p> Signup and view all the answers

    Which statement accurately describes electric potential?

    <p>It is measured in volts.</p> Signup and view all the answers

    Max Planck's quantum theory identifies X-rays by which characteristic?

    <p>Their energy measured in electron volts (eV).</p> Signup and view all the answers

    What occurs to electric charge on the surface of a conductor according to the Law of Concentration?

    <p>It is concentrated along the sharpest curvature.</p> Signup and view all the answers

    How does the distance from a radiation source affect the density of a radiographic image?

    <p>Greater distance decreases density.</p> Signup and view all the answers

    What does the term 'frequency' refer to in the context of electromagnetic energy?

    <p>Rate of rise and fall of the wave</p> Signup and view all the answers

    How is photon energy related to frequency?

    <p>Directly proportional</p> Signup and view all the answers

    What is the symbol used to represent wavelength?

    <p>λ</p> Signup and view all the answers

    What is the SI unit for measuring frequency?

    <p>hertz (Hz)</p> Signup and view all the answers

    Which of the following statements about wavelength is correct?

    <p>It is inversely proportional to frequency.</p> Signup and view all the answers

    Which of the following regions is fundamental for producing a high-quality radiograph?

    <p>X-ray region</p> Signup and view all the answers

    In what manner does ultrasound travel?

    <p>Requires matter to propagate</p> Signup and view all the answers

    What characterizes visible light in terms of measurement?

    <p>Described in terms of wavelength in nanometers</p> Signup and view all the answers

    Which statement about photon properties is accurate?

    <p>Photons are bundles of electromagnetic energy.</p> Signup and view all the answers

    What relationship does frequency have with the number of wavelengths passing a point?

    <p>Frequency is directly proportional to the number of wavelengths.</p> Signup and view all the answers

    What is the relationship between total momentum before and after an interaction?

    <p>Momentum is conserved during the interaction.</p> Signup and view all the answers

    What does 'work' represent in physics?

    <p>Force applied times the distance over which it is applied.</p> Signup and view all the answers

    Which statement accurately describes power in a physical context?

    <p>Power is the rate of doing work.</p> Signup and view all the answers

    What is the SI unit of power?

    <p>Watt</p> Signup and view all the answers

    Which process involves the transfer of heat through direct contact?

    <p>Conduction</p> Signup and view all the answers

    Which type of light has the shortest wavelength among the visible spectrum?

    <p>Violet light</p> Signup and view all the answers

    What is the primary effect of sunlight when it interacts with objects?

    <p>It heats substances</p> Signup and view all the answers

    In the electromagnetic wave equation, what does the variable 'c' represent?

    <p>Speed of light</p> Signup and view all the answers

    Which of the following types of light has a longer wavelength than visible light?

    <p>Infrared light</p> Signup and view all the answers

    What does refraction refer to in the context of light?

    <p>Deviation of light path</p> Signup and view all the answers

    What is the purpose of the Half Value Layer (HVL)?

    <p>To determine the thickness of absorber needed to halve radiation intensity</p> Signup and view all the answers

    How does minimizing the time of exposure affect radiation dose?

    <p>Significantly reduces the dose received by individuals</p> Signup and view all the answers

    What does the Tenth Value Layer (TVL) quantify?

    <p>The thickness needed to reduce radiation intensity to one-tenth</p> Signup and view all the answers

    What role does the International Commission on Radiological Protection (ICRP) serve?

    <p>Conducts research and provides recommendations on radiation protection</p> Signup and view all the answers

    What effect does increasing distance from a radiation source have on exposure levels?

    <p>Decreases exposure rapidly</p> Signup and view all the answers

    What is the primary purpose of collimation in radiography?

    <p>To restrict the useful x-ray beam</p> Signup and view all the answers

    Which material is commonly used in protective apparel to shield against radiation?

    <p>Lead-Impregnated Material</p> Signup and view all the answers

    What does ALARA stand for in the context of radiation safety?

    <p>As Low As Reasonably Achievable</p> Signup and view all the answers

    What is the SI unit for measuring current in a radiographic context?

    <p>Ampere</p> Signup and view all the answers

    What is the primary function of an intensifying screen in radiology?

    <p>To reduce the exposure time</p> Signup and view all the answers

    Which quantity best describes the measure of how fast something is moving?

    <p>Velocity</p> Signup and view all the answers

    What type of shielding is primarily recommended for individuals of childbearing age during radiographic procedures?

    <p>Gonadal shielding</p> Signup and view all the answers

    What construction feature is common in protective barriers used in radiation settings?

    <p>Lead-lined with a leaded-glass window</p> Signup and view all the answers

    What is a defining characteristic of ionizing radiation?

    <p>It is capable of ionization.</p> Signup and view all the answers

    What is the range of radiofrequency radiation used in MRI?

    <p>1 - 100 mHz</p> Signup and view all the answers

    Which statement about wave-particle duality is correct?

    <p>Photons exhibit both wave and particle characteristics.</p> Signup and view all the answers

    What does attenuation refer to in radiologic science?

    <p>The reduction of intensity due to scattering and absorption.</p> Signup and view all the answers

    How do microwaves interact with matter?

    <p>By inducing heat in larger particles.</p> Signup and view all the answers

    What is the range of electromagnetic radiation classified as microwaves?

    <p>Lower than infrared.</p> Signup and view all the answers

    Which electromagnetic radiation is of primary interest in radiologic science?

    <p>X-rays and gamma rays.</p> Signup and view all the answers

    What characteristic is true for visible light?

    <p>It is perceived by the human eye.</p> Signup and view all the answers

    Study Notes

    X-ray History

    • Leonard (1904): Used a Crookes tube and barium platinocyanide to demonstrate double emulsion film.
    • Clarence Dally (1904): The first recorded X-ray fatality.
    • William Rollins (Early 1900's): Pioneered the use of collimation and filtration in X-ray imaging.
    • H.C. Snook (1907): Introduced the interrupterless transformer (Snook Transformer).
    • William Coolidge (1913): Introduced the Coolidge X-ray tube.
    • Gustav Bucky (1913): Invented the stationary grid or "glitterblende".
    • Hollis Potter (1915): Invented the moving grid. The Potter Bucky (reciprocating grid) was introduced in 1921.
    • Light Amplifier (1946): Demonstrated at Bell Telephone Laboratories.
    • 1950s: Light amplifiers were adapted for fluoroscopy.
    • 1960s: Diagnostic ultrasound and gamma cameras emerged.
    • 1970s: Positron Emission Tomography (PET) and Computed Tomography (CT) were developed.
    • 1980s: Magnetic Resonance Imaging (MRI) became a widely accepted medical imaging modality.

    X-ray Examination Types

    • Radiography: Uses X-ray film and a ceiling-mounted X-ray tube to capture fixed images.
    • Fluoroscopy: Provides moving/dynamic images.

    X-ray Units of Measurement

    • X-ray Voltage: Measured in kilovolts peak (kVp) and determines the quality of the X-ray beam.
    • X-ray Current: Measured in milliamperes (mA) and determines the quantity of X-rays produced.

    Physics Fundamentals

    • Physics: The study of interactions between matter and energy.
    • Base Quantities: Mass, length, and time.
    • Secondary Quantities: Combinations of one or more base quantities.
    • Special Quantities: Exposure dose, equivalent dose, and radioactivity.

    Base Quantities and Units

    • Force: The rate of change of momentum.
    • Heat: The kinetic energy of the random motion of molecules.
    • Work: Force applied times the distance over which it is applied. Measured in Joules (J).
    • Power: The rate of doing work. Measured in Joules per second (Watts).

    Heat Transfer Methods

    • Conduction: Transfer of heat through a material by touching.
    • Convection: Mechanical transfer of "hot" molecules in a gas or liquid from one place to another.
    • Thermal Radiation: Transfer of heat by the emission of infrared radiation.

    Radiological Units

    • Roentgen (R): The unit of radiation exposure or intensity. Defined as the charge liberated per unit mass of air. Applies only to X-rays, gamma rays, and their interaction with air. This unit is also called Air Kerma (Gya).
    • Rad (Rad): Unit of absorbed dose. Defined as the energy absorbed per unit mass of a substance. This unit is also called Gray (Gyt).
    • Rem (Rem): Radiation equivalent man. Represents dose equivalent, effective dose, and equivalent dose. Used to express radiation received by workers and the population. This unit is also called Sievert (Sv).
    • Curie (Ci): Unit of radioactivity. This unit is also called Bequerel (Bq).

    Structure of Matter

    • Greek Atom: Atomos meant indivisible. The four basic substances were earth, water, air, and fire, and the four essences were wet, dry, hot, and cold.
    • John Dalton (1808): Dalton's atomic model: The Hook & Eye Affair (Dalton Atom). Classified elements by integral values of atomic mass.
    • Joseph John Thomson: Thomson's atomic model: The Plum Pudding (Thomson Atom). Identified electrons as integral parts of all atoms.

    Ernest Rutherford (1911)

    • Ernest Rutherford Model: Nuclear Model: Discovered and named the nucleus (small, dense, positively charged center).

    Niels Bohr (1913)

    • Niels Bohr atomic model: Mini Solar System: Improved Rutherford's model by suggesting that electrons revolve in fixed, well-defined orbits (electron orbital shells) around the nucleus.

    Dmitri Mendeleev

    • Created the first periodic table of elements arranged by their atomic numbers (number of protons).
    • Contains 118 elements.

    Fundamental Particles Summary

    • Nucleons: Protons (+) and Neutrons (O). They comprise quarks and gluons (subatomic particles).
    • Electron: Located in orbital shells. Mass = 9.1 x 10^-31 kg or 0.000549 amu, Charge = -1.
    • Proton: Located in the nucleus. Mass = 1.673 x 10^-27 kg or 1.00728 amu, Charge = +1.
    • Neutron: Located in the nucleus. Mass = 1.675 x 10^-27 kg or 1.00867 amu, Charge = 0.

    Atomic Mass Unit

    • Represents the mass of a neutral atom of an element.

    Electron Binding Energy

    • The strength of an electron's attachment to the nucleus.

    X-rays vs. Gamma Rays

    • X-Rays: Emitted from the electron cloud. Produced in diagnostic imaging systems. Interact with electrons. Behave like particles. Polyenergetic or heterogenous meaning they have varying energies.
    • Gamma Rays: Originate from the nucleus of radioactive atoms. Emitted spontaneously from radioactive material.

    Radiolucent vs. Radiopaque

    • Radiolucent: Allows X-rays to pass through. Appears black on a radiograph. e.g., Lung tissue
    • Radiopaque: Absorbs X-rays. Appears white on a radiograph. e.g., Bone.

    Inverse Square Law

    • The intensity of radiation at a location is inversely proportional to the square of the distance from the source.
    • If the Source-Image Distance (SID) is doubled, the density is reduced to 1/4.
    • Distance from the source primarily affects the density of the radiograph.

    Electricity, Magnetism, and Electromagnetism

    • Electrostatics: The study of stationary electric energy.

    • Electrostatic Laws:*

    • Distribution: Electric charge distribution is uniform throughout or on the surface.

    • Concentration: Electric charge is concentrated along the sharpest curvature of the surface.

    • Electric Potential: Measured in volts (V).

    • Electrification: Transfer of electric charges created through contact, friction, and induction.

    • Electrostatic Law: "Like charges repel and unlike charges attract."

    Max Planck

    • Synthesized our understanding of electromagnetic radiation.
    • Received the Nobel Prize in 1918.

    Particle Model: Max Planck's Quantum Theory

    • X-rays are identified by their energy (eV) and created at the speed of light (c). They behave like particles.

    Particle Accelerator (Atom Smasher)

    • Used to map the structure of the atomic nucleus.

    Summary of Key Facts

    • Leonard (1904): Double-emulsion film.
    • Clarence Dally (1904): First X-ray fatality.
    • William Coolidge (1913): Coolidge X-ray tube, a milestone in X-ray technology.
    • Hollis Potter (1915): Moving grid, an important development in X-ray imaging.
    • Radiolucent: Allows X-rays to pass through, appears black on a radiograph.
    • Radiopaque: Absorbs X-rays, appears white on a radiograph.
    • Inverse Square Law: Intensity of radiation is inversely proportional to the square of the distance from the source.
    • Max Planck's Quantum Theory: X-rays behave like particles.

    High Voltage Generator

    • Housed in an equipment cabinet positioned against a wall
    • Close to the x-ray tube
    • Newer generator designs are smaller
    • Operates as an induction device
    • Controls the kVp
    • Reduces patient radiation dose

    Autotransformer Law

    • States that the voltage received and provided by the transformer is directly proportional to the number of turns
    • Formula: Vs/Vp = Ns/Np (Vs = secondary voltage, Vp = primary voltage, Ns = secondary turns, Np = primary turns)

    Operating Console

    • Familiar to the radiologic technologist
    • Used to control the x-ray tube current and voltage applied to the x-ray tube
    • Controls Line compensation, kVp, mA, and exposure time
    • Most designed to operate on 220V power

    kVp Meter

    • Placed across the output terminals of the autotransformer
    • Reads the voltage, not the kVp
    • Pre-reading kVp meter allows the voltage to be monitored before an exposure

    Radiation Quantity (mAs)

    • Represents the number of x-rays and the intensity of the x-ray beam
    • Controlling factor of current, high number of electrons, higher heat provided to the x-ray tube
    • Units: mR, mGy or mR/mGya, mAs

    Filament Temperature

    • Controlled by the filament current, which determines the number of electrons emitted by the filament

    Filament Current

    • Measured in Amperes (A)
    • X-ray tube is controlled through a separate circuit called the Filament Circuit
    • Operates at about 3 to 6 Ampere

    Space Charge Effect

    • A phenomena via electrostatic repulsion of the electron cloud near the filament

    Thermionic Emission

    • The release of electrons from a heated filament

    Precision Resistors

    • Used to reduce the voltage to a value that corresponds to the selected milliamperage

    Falling Load Generator

    • Exposure begins at maximum mA, then drops as the anode heats, resulting in minimum exposure time

    Milliamperage x Exposure Time (mAs)

    • The product of x-ray tube current (mA) and exposure time
    • Represents the quantity of electrostatic charge (C)

    mA Meter

    • Monitors the x-ray tube current
    • Connected at the center of the secondary winding of the high-voltage transformer
    • Ensures electrical safety

    Filament Transformer

    • “Filament heating isolation step-down transformer”
    • Receives voltage from the mA selector switch
    • Steps down the voltage to approximately 12V
    • Provides current to heat the filament
    • Primary Winding: Thin copper, 0.5 to 1 Ampere, 150V approximately
    • Secondary Winding: Thick, 5 to 8 Ampere, 120V

    Exposure Timers

    • Devices that control the duration of the x-ray exposure
    • Four main types:
      • Synchronous Timer
      • Electronic Timer
      • mAs Timer
      • AEC (Automatic Exposure Control)

    Guard Timer

    • Terminates the exposure after a prescribed time (usually 6 seconds)
    • Used to ensure safety and prevent overexposure

    Synchronous Timer

    • Motor-driven precision device
    • Drives a shaft at precisely 60 revolutions per second
    • Cannot be used for serial exposures

    Electronic Timer

    • Most sophisticated, complicated, and accurate type of x-ray exposure timer
    • Allows a wide range of time intervals
    • Accurate to intervals as small as 1ms
    • Used for rapid serial exposures, suitable for interventional radiology
    • Most exposure timers are electronic

    mAs Timer

    • Monitors the product of mA and exposure time (electrostatic charge - C)
    • Terminates the exposure when the desired mAs value is attained
    • Provides the highest safe tube current for the shortest exposure for any mAs selected

    Automatic Exposure Control (AEC)

    • Device that measures the quantity of radiation reaching the image receptor (IR)
    • Automatically terminates the exposure when the IR has received the required radiation intensity

    Solid-State Detectors (SSD)

    • Used to check timer accuracy (as short as 1ms)

    High Voltage Generator

    • Increases the output voltage from the autotransformer to the kVp necessary for x-ray production
    • Heat generated is conducted to oil, which is used primarily for electrical insulation ("DIALA V OIL")

    Three Primary Parts

    • High Voltage Transformer, Filament Transformer, and Rectifiers

    High Voltage Transformer

    • Step-up transformer
    • Secondary voltage (kVp) > Primary voltage (V)
    • Secondary current (mA) < Primary current (A)
    • Secondary windings > primary windings
    • Voltage waveform: Sinusoidal

    Turns Ratio

    • The ratio of the number of secondary windings to the number of primary windings
    • Example: 500:1 and 1000:1
    • Directly proportional to the voltage
    • Inversely proportional to the current

    Rectification

    • The process of converting alternating current (AC) to direct current (DC)
    • Xrays are produced by the acceleration of electrons from the cathode to the anode and cannot be produced by electrons flowing in the reverse direction (Direct Current)

    Voltage Rectification

    • Ensures that electrons flow from the cathode to the anode only

    Rectifier

    • An electronic device that allows current to flow in only one direction

    Diode

    • An electronic device that contains two electrodes
    • All diode rectifiers were once vacuum tubes called “Valve tubes” but have been replaced by solid-state rectifiers made of silicon.

    Semiconductor

    • Materials that fall between insulators and conductors in their ability to conduct electricity

    P-Type Semiconductor

    • Have loosely bound electrons (free to move)
    • Have spaces called holes (no electrons)
    • Holes are as mobile as electrons

    Solid-State P-N Junction

    • N-type material placed in contact with p-type crystal
    • Conducts electricity in only one direction
    • Solid-State Diode: A rectifier

    Half-Wave Rectification

    • Contains 0, 1, or 2 diodes
    • Voltage is now allowed to swing negatively during the negative half of its cycle, producing 60 x-ray pulses per second.
    • Wastes half the supply of power and requires twice the exposure time

    Full-Wave Rectification

    • Contains at least 4 diodes
    • Negative half-cycle corresponding to the inverse voltage is reversed
    • Produces 120 x-ray pulses per second
    • Exposure time is cut in half
    • Used in almost all stationary x-ray systems.

    Single-Phase Power

    • Results in a pulsating x-ray beam
    • X-rays produced have a value near zero
    • Single Phase Halfwave voltage ripple: 100%
    • Single Phase Fullwave voltage ripple: 100%
    • Voltage varies from zero to maximum

    Three-Phase Power

    • Voltage impressed across the x-ray tube is nearly constant
    • Produces 6 pulses per 1/60 second
    • Voltage never drops to zero during exposure
    • Disadvantages: Size and Cost
    • Requires 10 kVp reduction
    • 6-Pulse voltage ripple: 14%

    The X-ray Tube

    • Special type of diode (anode and cathode)
    • Converts electrical energy to electromagnetic energy

    Formula

    • (0.7)(mA x kVp)/1000 (for single-phase)

    Energy

    • The ability to do work.
    • Can be transformed from one form to another but cannot be created or destroyed.
    • Measured in Joules (J).

    Acceleration

    • Rate of change of velocity with time.
    • How quick or slow an object is moving.
    • Measured in meters per second squared (m/s2).
    • Calculated by dividing velocity by time (acceleration = velocity/time).

    Weight

    • Force experienced due to the downward pull of gravity.
    • Weight = mass x gravity (Wt = (m)(g))
    • Measured in Newtons (N) or pounds (lbs).

    Momentum

    • The product of mass and velocity.

    Centrifugal Force

    • The force that causes an object to fly out from the center of a circular path.
    • Example: When an electron travels in a circle, the centrifugal force pushes it to leave the atom.

    Newton's Law of Motion

    • Law of Inertia: A body at rest will remain at rest, and a body in motion will remain in motion at a constant velocity unless acted upon by an external force.
    • Law of Force: The force (F) acting on an object is equal to its mass (m) multiplied by its acceleration (a). (F = (m)(a)). Force can be described as a push or pull.
    • Law of Action/Reaction: For every action, there is an equal and opposite reaction.

    Molecules

    • The smallest unit of a compound, composed of two or more atoms.

    Water

    • 80% of the human body.

    Radioactivity

    • The emission of particles and energy by an unstable atom to become stable.

    Radionuclide

    • An atom that undergoes radioactive decay.

    Radioactive Disintegration/Radioactive Decay

    • The process by which the nucleus of an unstable atom emits particles and energy to transform itself into a stable atom.

    Half-Life

    • The time required for a radioactive substance to decay to half of its original activity.
    • Half-life starts at 50%. 100% is the original value and does not count as half-life activity.
    • Radioactive decay formula: Activity Remaining = (Original value/activity)(0.5)n (number of half-lives).
    • n = number of half-lives.

    Alpha Decay/Helium Nucleus

    • Proton and neutron-rich.
    • The nucleus emits an alpha particle (two protons and two neutrons), reducing its atomic number by 2 and its mass number by 4.
    • Most ionizing and destructive type, least penetrating.

    Beta Minus Decay

    • Negatron decay/emission, neutron-rich.
    • The nucleus emits a beta minus particle (an electron) and an antineutrino, increasing its atomic number by 1.
    • Produced in nuclear reactors.

    Beta Plus Decay

    • Positron decay, proton-rich.
    • The nucleus emits a positron (antimatter) and a neutrino, decreasing its atomic number by 1.
    • Produced in cyclotrons.

    Electron Capture/K Capture Decay

    • Positron-rich nucleus.
    • One proton is converted into a neutron, capturing an electron from the innermost shell (K-shell) of the atom.
    • Emits characteristic X-rays from the K-shell.
    • Decreases in atomic number by 1.

    Gamma Decay

    • Excess energy in the nucleus is released as a gamma ray photon.
    • Doesn't change the atomic number or mass number.
    • Metastable state, isomeric transition.

    Electromagnetic Wave

    • All electromagnetic waves travel at the speed of light (approximately 3 x 108 m/s).
    • Electromagnetic wave equation: c = fλ where c is the speed of light, f is frequency, and λ is the wavelength.

    Electromagnetic Spectrum

    • A continuum of electromagnetic energy, ranging from long wavelengths (radio waves) to short wavelengths (gamma rays).

    Visible Light

    • ROYGBV (red, orange, yellow, green, blue, indigo, violet)
    • The visible light spectrum ranges from approximately 400 nm (violet) to 700 nm (red), with violet having the highest frequency and shortest wavelength.

    Refraction

    • The deviation of light as it passes from one transparent medium to another, causing a change in direction.
    • Example: A straw in a glass of water appears broken because light bends as it passes from air to water.

    Sunlight

    • A mixture of visible light and invisible light such as infrared and ultraviolet light.

    Infrared Light

    • Longer wavelength than visible light.
    • Shorter wavelength than microwaves.
    • Heat any substance on which it shines (radiant heat).

    UV Light

    • Shorter wavelength than visible light.
    • Can cause skin damage.

    Direct Current

    • Electrons flow in one direction only, forming a straight line.

    Magnetic Dipole

    • A small magnetic field created by the orbiting electrons of an atom.

    Magnetic Domain

    • Accumulation of many atomic magnets with aligned dipoles.

    Magnetic Permeability

    • The ability of a material to attract lines of magnetic field intensity.

    Paramagnetic

    • Materials weakly attracted to a magnetic field.
    • Example: Gadolinium.

    Ferromagnetic

    • Materials strongly magnetized.
    • Example: Iron, nickel, cobalt.

    Magnetic Susceptibility

    • The degree to which a material can be magnetized.
    • Wood has a low magnetic susceptibility while iron has a high magnetic susceptibility.
    • Hysteresis: a condition where some materials that are very susceptible are also reluctant to lose their magnetism.

    Magnetic Induction

    • The process of making a ferromagnetic material magnetic.

    Magnetic Force

    • The force of attraction between unlike poles or repulsion between like poles.
    • Directly proportional to the product of the magnetic pole strengths.
    • Inversely proportional to the square of the distance between them.

    Magnetic Field Strength

    • SI unit: Tesla (T).
    • Older unit: Gauss (G).
    • 1 Tesla = 10,000 Gauss.

    Hans Oersted's Law of Electromagnetism

    • Electricity can be used to generate magnetic fields.
    • Any charge in motion produces a magnetic field.
    • The basis for the electric motor.

    Solenoid

    • A coil of wire wound into a helix, creating a magnetic field when electricity flows through it.

    Electromagnet

    • A current-carrying coil of wire wrapped around a ferromagnetic core.
    • Intensifies the induced magnetic field.
    • Advantage: Its magnetic field can be adjusted or turned on and off.

    Four Magnetic States of Matter

    • Non-Magnetic: Unaffected by magnetic fields (example: wood).
    • Diamagnetic: Weakly repelled by magnetic fields (example: water and plastic).
    • Paramagnetic: Weakly attracted to magnetic fields (example: gadolinium).
    • Ferromagnetic: Strongly magnetized by magnetic fields (example: iron, nickel, cobalt).

    Michael Faraday's Law of Electromagnetic Induction

    • First law of electromagnetism.
    • A changing magnetic field induces an electric current in a conductor.
    • The magnitude of the induced current depends on:
      • Strength of the magnetic field.
      • Velocity of the magnetic field as it passes the conductor.
      • Angle of the conductor to the magnetic field.
      • Number of turns in the conductor.

    Electromagnetic Devices

    • Electric Motor: Converts electrical energy into mechanical energy.
    • Electric Generator: Converts mechanical energy into electrical energy.
    • Transformer: Changes the intensity of alternating voltage and current.
    • Induction Motor: A type of motor used to power the rotating anode of an x-ray tube.

    Transformer

    • Works on alternating current only (AC).
    • Direct current (DC) does not induce a current in the secondary coil due to its constant voltage.
    • Transformer Law: Change in voltage is directly proportional to the ratio of the number of turns in the secondary coil (Ns) to the number of turns in the primary coil (Np). Formula: Vs/Vp = Ns/Np.
    • Vs - Secondary Circuit, Vp - Primary Circuit, Ns - Secondary coil turn ratio, Np - Primary coil turn ratio.

    Step-Up Transformer

    • Turns ratio greater than 1.
    • Primary side: low voltage, high current.
    • Secondary side: high voltage, low current.

    Step-Down Transformer

    • Turns ratio less than 1.
    • Primary side: high voltage, low current.
    • Secondary side: low voltage, high current.

    Effect of Transformer Law on Current

    • Change in current and change in voltage are inversely related.

    Types of Transformers

    • Closed-Core Transformer: Square core of ferromagnetic materials built up of laminated layers of iron.
    • Autotransformer: Consists of one winding of wire and varies in voltage and current by self-induction.
    • Shell-Type Transformer: Confines more of the magnetic field lines of the primary winding.

    Eddy Current

    • Current that opposes the magnetic field that created it.
    • Causes a loss of transformer efficiency.

    X-ray Imaging System

    • Three main components:
      • Operating Console
      • High-voltage Generator
      • X-ray tube

    Fluoroscopic X-ray Tube

    • Located under the x-ray table.

    Radiographic X-ray Tube

    • Attached to an overhead movable crane assembly.

    Examination Couch/Table

    • Must be transparent to x-rays as possible.
    • Carbon fiber couches are strong and absorb little radiation.

    Radiation Quality (kVp)

    • Pertains to the quality and penetrability of the x-ray beam.
    • Controlled by the voltage.
    • Expressed in kilovolts peak (kVp) or half-value layer (HVL).

    Line Compensator

    • Measures voltage supplied to an x-ray imaging system and adjusts the voltage precisely to 220 volts.

    Autotransformer

    • Consists of only one winding of wire and one iron core.
    • Supplies a precise voltage to the filament circuit and the high-voltage circuit.
    • Designed to step up the voltage to twice the input voltage value.

    Radiation Protection

    • Radiation protection minimizes the risk of health effects associated with exposure to ionizing radiation.
    • International Commission on Radiological Protection (ICRP) sets recommended dose limits for radiation exposure.
    • The current annual whole-body dose limit for radiation workers is 20 mSv (2000 mrem).
    • The recommended dose limit for pregnant radiation workers is 0.5 mSv for the entire pregnancy, and 5 mSv for the fetus.

    Quality Assurance and Quality Control

    • Quality assurance monitors the entire radiology process, including scheduling, patient preparation and image interpretation.
    • Quality control focuses on evaluating and maintaining the technical performance of imaging equipment.
    • Key aspects of quality control include:
      • Collimation Tests: Ensures the collimator shutters are accurately aligned with the image receptor and minimize radiation exposure to areas outside the intended field.
      • Filtration: Proper filtration ensures appropriate radiation beam hardening, protecting the patient from unnecessary exposure. Minimum total filtration of 2.5 mm Al is required.
      • Focal Spot Size: Determines the spatial resolution of the image. Evaluated annually or whenever an x-ray tube is replaced.

    Focal Spot Size Measurement

    • Three tools are commonly used for measuring focal spot size:
      • Pinhole camera
      • Star pattern test tool
      • Slit camera

    Regular Equipment Testing

    • Regular testing ensures continued optimal performance of radiographic equipment.
    • Key tests and their frequencies:
      • kVp Calibration: Ensures the actual kVp applied is within 10% of the indicated kVp. Performed annually or whenever high-voltage generator components are changed.
      • Exposure Time Accuracy: Ensures the exposure time is within 5% of the indicated time for exposures greater than 10ms.
      • Exposure Linearity: Ensures the exposure values are consistent across various mA stations.
      • Screen-Film Contact: Evaluates contact between the film and intensifying screen, using wire mesh pattern to analyze.

    Imaging Science and Informatics

    • Information Technology: Use of computers to manage medical information, such as storage, retrieval, transmission, and manipulation.
    • Computer Science: Applies computational technologies for medical information management, improving efficiency and accuracy.
    • Information Science: An interdisciplinary field that focuses on the analysis, collection, classification, and retrieval of information.
    • Biomedicine: An interdisciplinary field that combines technological advances with biological principles to understand and address health challenges.

    Matter

    • Anything that occupies space and has mass
    • Distinguishing characteristic is mass (measured in kg)

    Atoms

    • “A (not) (Tomon/Tomos) to cut”
    • Smallest particle of an element
    • Composed of:
      • Protons
      • Neutrons
      • Electrons

    Centrifugal Force

    • “Flying-out-from-the-center force”
    • The force that causes an electron to travel straight and leave the atom

    Molecules

    • Group of atoms, smallest unit of a compound
    • Example: NaCI

    Water

    • 80% of the human body

    Radiation Physics

    • Electrical Energy - Done when an electron moves through the electrical potential difference. Electricity
    • Thermal energy - Energy of motion at the atomic and molecular level. Temperature.
    • Nuclear energy - Energy contained in the nucleus of an atom. Nuclear reaction
    • Electromagnetic energy (EMR) - Radiation is a transfer of energy. Ultrasound is a form of radiation but not an ionizing radiation.

    Radioactivity

    • Emission of particles and energy in order to become stable

    Radionuclide

    • Atoms involved and the only nuclei that undergoes radioactive decay

    Radioactive Disintegration/Radioactive Decay

    • Nucleus emits particles and energy to transform itself into another atom to reach stability

    Half-life

    • The time required for a quantity of radioactivity to be reduced to one-half of its original value
    • Half-life starts at 50%. 100% is the original value (does not count as half-life activity)

    Radioactive Decay Formula

    • Activity Remaining = (Original value/activity)(0.5)n (number of half-lives)

    Alpha Decay/Helium nucleus

    • Proton and Neutron Rich
    • Alpha particles - Most ionizing and destructive type, least penetrating
    • -2 Proton and -2 Neutron (A-4)

    Beta Minus Decay

    • Negatron Decay/Emission, Neutron Rich
    • Emission of Negaton and an Anti-Neutrino
    • Produced in Nuclear Reactors
    • 1 Neutron is converted into a positive and negative
    • Increase in Atomic number by 1
    • Isobaric Transition

    Beta Plus Decay

    • Positron Decay, Proton Rich
    • One proton is converted to a neutron and a positive electron called "Positron"
    • Emission of Positron (Antimatter) and a Neutrino
    • Produced in Cyclotron
    • 1 positive is converted into a Neutron and a positron
    • Decrease in atomic number by 1
    • Isobaric Transition

    Electron Capture/K Capture Decay

    • Positron Rich Nucleus
    • Proton is converted into a Neutron
    • Produced in Characteristic X-rays from the K-shell
    • Positive is converted into a neutron
    • Decrease in atomic number by 1
    • Isobaric Transition

    Gamma Decay

    • Excess energy in the nucleus is being release in the form of gamma ray
    • Metastable state
    • No change in atomic number
    • Isomeric Transition

    Photon

    • Smallest quantity of any type of electromagnetic energy. Frequency
    • May be pictured as a small bundle of energy, sometimes called a quantum, that travels through space at the speed of light (3 x 108 m/s.)
    • No Mass, no Charge
    • Waveform: Sinusoidal Fashion
    • Photon energy and Frequency is directly proportional
    • Small bundle of energy

    Quantum

    • Directly proportional to Energy
    • Number of wavelength that pass a point of observation per second

    Wavelength (λ)

    • Represented by Greek symbol λ or Lambda
    • Distance from One Crest to another/One Valley to another
    • One point on the sine wave to the next corresponding point
    • Inversely proportional to the Frequency

    Wave Equation

    • These are used for both sound & electromagnetic energy

    X-ray Region

    • Fundamental to producing a high quality radiograph

    Radiofrequency Region

    • Fundamental aspect in Magnetic Resonance Imaging

    Ultrasound

    • The wave of moving molecules
    • It requires matter
    • It cannot exist in a vacuum

    Visible Light

    • It is described in terms of wavelength, measured in nanometer (nm)
    • Interacts with rods and cones of the eye
    • Red has the longest wavelength (700nm) but the shortest frequency. Exits with velocity (3 x 108 m/s)
    • Uncharged particles do not have electric fields. Wavelength: 10-10 – 10-14m

    Electric Field

    • Causes charged particles to move from one pole to another
    • Positive charge: Outward
    • Negative charge: Toward

    Electrostatic force

    • The force of attraction between unlike charges or repulsion between like charges
    • Directly proportional to the product of the charges
    • Inversely proportional to the square of the distance between them

    Coulomb’s Law

    • The electrostatic force is directly proportional to the product of the electrostatic charges and inversely proportional to the square of the distance between them

    Semiconductor

    • Can be conductive and the basis of computers
    • Example: Silicon, & Germanium

    Law of Conservation of Matter

    • It states that matter can be neither created nor destroyed

    Law of Conservation of energy

    • It states that energy may be transformed from one form to another but cannot be created or destroyed

    Magnetism

    • Magnetic dipole is a small magnetic field created by an electron's orbit.
    • Magnetic domains: Accumulation of many atomic magnets with aligned dipoles, randomly distributed.
    • Magnetic permeability: The ability of a material to attract lines of magnetic field intensity.
    • Paramagnetic materials are weakly attracted to a magnetic field (e.g., Gadolinium).
    • Ferromagnetic materials are strongly magnetized (e.g., Iron, Nickel, Cobalt).
    • Magnetic susceptibility: The degree to which a material can be magnetized.
    • Wood has low magnetic susceptibility.
    • Iron has high magnetic susceptibility.
    • Hysteresis: Some materials with high magnetic susceptibility are also reluctant to lose their magnetism.
    • Magnetic force: The force of attraction between unlike poles or repulsion between like poles.
    • Magnetic force is directly proportional to the product of the magnetic pole strengths.
    • Magnetic force is inversely proportional to the square of the distance between the poles.

    Types of Magnets

    • Naturally occurring magnets: These magnets get their magnetic properties from Earth. An example is lodestone, which was found in Magnesia.
    • Artificially produced permanent magnets: Magnetism is induced artificially in these types of magnets. Examples include bar magnets and horseshoe-shaped magnets.
    • Electromagnets: Consists of a coil of wire wrapped around an iron core, which intensifies the magnetic field.

    Magnetic Induction

    • Magnetic induction is the process of making ferromagnetic material magnetic.

    Three Principal Types of Magnets

    • Naturally Occurring Magnets
    • Get their magnetic properties from Earth, example: Lodestone (lead stone) - Magnesia
    • Artificially Produced Permanent Magnets
    • Magnetism is induced artificially, examples: A bar of horseshoe-shaped magnet, Compass
    • Electromagnets
      • A coil of wire wrapped around an iron core that intensifies the magnetic field

    Hans Christian Oersted's Law of Electromagnetism:

    • Electricity can generate magnetic fields.
    • Any charge in motion induces a magnetic field.
    • Electric current produces mechanical motion, which is the basis of the electric motor.

    Four Magnetic States of Matter

    • Non-magnetic: Unaffected by a magnetic field (e.g., wood).
    • Diamagnetic: Weakly repelled by a magnetic field (e.g., water and plastic).
    • Paramagnetic: Weakly attracted to a magnetic field (e.g., Gadolinium).
    • Ferromagnetic: Strongly magnetized by a magnetic field (e.g., Iron, Nickel, Cobalt).

    Solenoid

    • A coil of wire that creates a magnetic field when electricity flows through it

    Electromagnet

    • A current-carrying coil of wire wrapped around an iron core that intensifies the induced magnetic field
    • It has the advantage that the magnetic field can be adjusted or turned on and off.

    Michael Faraday's Law of Electromagnetic Induction

    • The first law of electromagnetism.
    • Observed that a changing magnetic field creates an electric current.

    Factors Affecting the Magnitude of Induced Current

    • Strength of the magnetic field.
    • Velocity of the magnetic field as it passes the conductor.
    • The angle of the conductor to the magnetic field.
    • The number of turns in the conductor.

    Electromagnetic Devices

    • Electric Motor: Electric current produces mechanical motion.
    • Electric Generator: Mechanical motion produces electric current.

    Transformer

    • A device that changes the voltage and current of alternating current (AC) electricity.
    • Works on AC only. DC induces no current in the secondary coil.

    Transformer Law

    • Change in voltage is directly proportional to the ratio of the number of turns in the secondary coil (Ns) to the number of turns in the primary coil (Np).
    • Formula: Vs/Vp = Ns/Np.
    • Vs - Secondary Circuit, Vp - Primary Circuit, Ns - Secondary coil turn ratio, Np - Primary coil turn ratio.

    Types of Transformers

    • Step-up Transformer: Turns ratio is greater than 1.
      • Primary side: low voltage, high current.
      • Secondary side: high voltage, low current.
    • Step-down Transformer: Turns ratio is less than 1.
      • Primary side: High voltage, low current.
      • Secondary side: Low voltage, high current.

    Effect of Transformer Law on Current

    • Change in current and change in voltage are inversely related.

    Types of Transformers

    • Closed-core Transformer: Square core of laminated ferromagnetic materials; reduces energy losses caused by eddy current, leading to greater efficiency.
    • Eddy Current: Current that opposes the magnetic field that induced it, leading to losses in transformer efficiency.
    • Autotransformer: Consists solely of one winding of wire and varies voltage and current through self-induction.
    • Shell-type Transformer: Confines more of the magnetic field lines of the primary winding, making it more efficient than the closed-core transformer.

    X-Ray Imaging System

    • Three Main Components:
      • Operating Console: Controls the x-ray system.
      • High Voltage Generator: Supplies high voltage to the x-ray tube.
      • X-Ray Tube: Produces x-rays.

    Types of X-Ray Tubes

    • Fluoroscopic X-Ray Tube: Located under the x-ray table.
    • Radiographic X-Ray Tube: Attached to an overhead movable crane assembly.

    Examination Couch/Table

    • Must be transparent to x-rays as much as possible.
    • Carbon fiber couches are strong and absorb little radiation.

    Radiation Quality (kVp)

    • The quality and penetrability of the x-ray beam.
    • Controlled by voltage.
    • Expressed in kVp or Half Value Layer (HVL).

    Line Compensator

    • Measures voltage provided to the x-ray imaging system and adjusts it to precisely 220V.

    Autotransformer

    • Consists of only one winding of wire and one core.
    • Supplies a precise voltage to the filament circuit and high-voltage circuit.
    • Designed to step up voltage to approximately twice the input voltage value.

    Induction Motor

    • A type of motor used to power the rotating anode of an x-ray tube.

    Radiation Protection

    • ALARA stands for As Low As Reasonably Achievable
    • Cardinal Principle includes Shielding, Time, Distance
    • Filtration absorbs low-energy x-rays
    • Collimation restricts the useful x-ray beam, reduces scatter radiation, improves image contrast
    • Intensifying Screens reduce x-ray exposure by more than 95%
    • Protective Apparel includes lead-impregnated material, examples are gloves, shields, aprons
    • Gonadal Shielding is used with all persons of childbearing age
    • Protective Barriers are lead-lined with a leaded-glass window, a complete concrete wall should be 6 inches thick

    Physics

    • Radiation is the emission of energy from matter, especially in the form of particles or electromagnetic waves
    • Non-ionizing Radiation is not capable of removing or ejecting an outer-shell electron, examples include Ultrasound, Magnetic Resonance Imaging (MRI), and Therapeutic Ultrasound,
    • Electromagnetic Radiation exists over a wide range called an energy continuum
    • Photon is the smallest quantity of any type of electromagnetic energy, it is a small bundle of energy that travels through space at the speed of light, has no mass, and no charge
    • Frequency (f) is the rate of rise and fall, measured in Hertz (Hz), 1 Hz is 1 cycle/second
    • Wavelength (λ) is the distance from one crest to another or one valley to another, inversely proportional to frequency
    • Quantum is directly proportional to energy
    • X-Ray Region is fundamental to producing a high-quality radiograph
    • Radiofrequency Region is fundamental in Magnetic Resonance Imaging (MRI)

    Radioactivity

    • Curie (Ci) and Becquerel (Bq) are units of radioactivity
    • Whole Body Dose Limit is the maximum amount of radiation that a person can be exposed to in a given period of time, the current whole body dose limit is 1 mSv/wk (100 mRem/wk)
    • Pregnant Radiographer Dose Limit is 0.5 mSv/wk (50 mRem/wk), the dose limit for the fetus is 5 mSv (500 mRem)

    Radiographic Equipment

    • Scheduled Maintenance is a planned program of parts replacement at regular intervals, replacing parts before they fail can prevent unexpected downtime
    • Non-Scheduled Maintenance occurs when there is an unexpected machine failure
    • Collimation Test evaluates alignment, misalignment must not exceed 2% of the SID, Positive beam-limiting collimators (PBL) automatically sense the size of the IR and adjust the collimating shutters to that size
    • Filtration is the most important patient protection characteristic of a radiographic imaging system, the minimum total filtration is 2.5 mm Al and is evaluated annually
    • Focal Spot Size determines spatial resolution, evaluated annually or whenever an x-ray tube is replaced
    • kVp Calibration is measured kVp should be within 10% of the indicated kVp, evaluated annually or whenever high-viktage generator components have changed significantly
    • Exposure Time Accuracy is evaluated using solid-state radiation detectors, exposure times greater than 10 ms should be within 5%, for exposure times less than 10ms 20% accuracy is acceptable
    • Exposure Linearity must be within 10% for adjacent mA stations, evaluated using a precision radiation dosimeter that measures radiation intensity
    • Screen Film Contact should be evaluated once or twice a year, done by radiographing a wire mesh pattern

    Quality Assurance

    • Quality Assurance monitors proper patient scheduling, reception, preparation, and image interpretation, deals with people, includes radiologists and imaging service management
    • Quality Control monitors the equipment, three tools used to measure focal spot size are the pinhole camera, the star pattern, and the slit camera

    Image Quality

    • Spatial Resolution is determined by the focal spot size of the x-ray tube
    • Line-Pair Test Tool determines limiting spatial frequency

    Testing

    • kVp, Timer, Output, mR/mAs, Inherent Filtration, Focal Spot Size, Central Beam Alignment, Congruence of Radiation, and Optical Field, Grid Alignment are all tests performed to ensure quality control of radiographic equipment

    Information Technology

    • Information Technology is the use of computers to store, retrieve, transmit, and manipulate data or information
    • Computer Science is widely used in medicine for the management of computer information management systems in hospitals
    • Information Science is an interdisciplinary field primarily concerned with the analysis, collection, classification, and retrieval of information, has two components: practical and theoretical

    Biomedicine

    • Biomedicine is an integral part of how health, illness, and individual identity are understood

    ### Atomic Structure

    • Atomic Mass Number (A): The number of protons and neutrons in the nucleus, and is directly related to the strength of binding energy.
    • Atomic Number (Z): The number of protons in the nucleus, determining the chemical behavior of an atom.
    • Isotopes: Same number of protons but different number of neutrons.
    • Electron Arrangement: The number of electrons in the outermost shell of an atom determines the group in the periodic table, the valence, and how the element may react with other elements.
    • Maximum Electrons Per Shell: Formula: 2n2, where n is the shell number (also known as Principal Quantum Number).
    • Centripetal Force: Center-seeking force that keeps an electron in orbit.
    • Centrifugal Force: Flying-out-from-the-center force that causes an electron to travel straight and leave the atom.
    • Octet Rule: No outer shell can contain more than 8 electrons.

    ### Nuclear Arrangement

    • PSZ (Isotope): Same atomic number (Z).
    • BSA (Isobar): Same atomic mass (A).
    • NSN (Isotone): Same neutron number (N).
    • MSS (Isomer): Same in all aspects, but differ in energy state (Metastable).

    ### Combination of Atoms

    • Covalent Bonds: Atoms share electrons, example: H2O (Water).
    • Ionic Bonds: Atoms gain or lose electrons due to electrostatic force.

    ### Matter

    • Anything that occupies space and has mass.
    • The distinguishing characteristic of matter is mass (measured in kg).
    • Atoms - A (not) (Tomon/Tomos) to cut (Newton's word for atom).
    • Total momentum before any interaction is equal to the total momentum after the interaction, represented by p.
    • P = (m)(v).

    ### Work

    • Force applied times the distance over which it is applied.
    • Unit is Joule (J), W = (F)(d).

    ### Power

    • Rate of doing work.
    • SI unit is Joules/second (Watt).

    ### Energy

    • Electrical Energy: Done when an electron moves through an electrical potential difference.
    • Thermal Energy: Energy of motion at the atomic and molecular level.
    • Nuclear Energy: Energy contained in the nucleus of an atom.
    • Electromagnetic Energy (EMR): Radiation is a transfer of energy. Ultrasound is a form of radiation, but not an ionizing radiation.

    ### Heat

    • Kinetic energy of the random motion of molecules.
    • Transfer by conduction, convection, and radiation.

    ### Conduction

    • The transfer of heat through a material by touching.

    ### Convection

    • The mechanical transfer of “hot” molecules in a gas or liquid from one place to another.

    ### Thermal Radiation

    • Transfer of energy, usually infrared energy, through a vacuum.

    ### Radioactivity

    • The emission of particles and energy in order to become stable.

    ### Radionuclide

    • Atoms involved in radioactive decay, the only nuclei that undergo radioactive decay.

    ### Radioactive Disintegration/Radioactive Decay

    • The nucleus emits particles and energy to transform itself into another atom to reach stability.

    ### Half-Life

    • The time required for a quantity of radioactivity to be reduced to one-half of its original value.
    • The half-life starts at 50%, 100% is the original value (does not count as half-life activity).

    ### Radioactive Decay Formula

    • Activity Remaining = (Original value/activity)(0.5)n (number of half-lives)

    ### Alpha Decay/Helium Nucleus

    • Proton and Neutron Rich.
    • Alpha particles - Most ionizing and destructive type, least penetrating.
    • -2 proton and -2 neutron (A-4).

    ### Beta Minus Decay

    • Negatron Decay/Emission, Neutron Rich.
    • Emission of Negaton and an Anti-Neutrino.
    • Produced in Nuclear Reactors.
    • 1 Neutron is converted into a proton and an electron.
    • Increase in Atomic number by 1.
    • Isobaric Transition.

    ### Beta Plus Decay

    • Positron Decay, Proton Rich.
    • One proton is converted to a neutron and a positive electron called "Positron."
    • Emission of Positron (Antimatter) and a Neutrino.
    • Produced in Cyclotron.
    • 1 positive is converted into a Neutron and a positron.
    • Decrease in atomic number by 1.
    • Isobaric transition.

    ### Electron Capture/K Capture Decay

    • Positron Rich Nucleus.
    • Proton is converted into a Neutron and an electron from the K-Shell is captured.
    • Produced in Characteristic X-rays from the K-shell.
    • Decrease in atomic number by 1.
    • Isobaric Transition.

    ### Gamma Decay

    • Excess energy in the nucleus is being released in the form of a gamma ray.
    • Metastable state.
    • No change in atomic number.
    • Isomeric Transition.

    ### Molecules

    • A group of atoms, the smallest unit of a compound.

    ### Water

    • 80% of the Human body.

    ### Photon

    • The smallest quantity of any type of electromagnetic energy.
    • A photon may be pictured as a small bundle of energy, sometimes called a quantum, that travels through space at the speed of light (3 × 108 m/s).
    • No mass, no charge.
    • Waveform: Sinusoidal Fashion
    • Photon energy and Frequency are directly proportional.

    ### Quantum

    • Small bundle of energy, sometimes called a quantum, that travels through space at the speed of light (3 × 108 m/s).

    ### Frequency

    • Rate of rise and fall of photons in electrical and magnetic fields.
    • Symbol: f.
    • SI Unit: hertz (Hz).
    • 1 Hz: 1 cycle/second.
    • It is equal to the number of crests or valleys that pass the point of an observer per unit time.
    • It is inversely proportional to the wavelength.

    ### Wavelength (λ)

    • Distance from one crest to another/one valley to another.
    • One point on the sine wave to the next corresponding point.
    • Inversely proportional to the frequency.

    ### Wave Equation

    • Used for both sound and electromagnetic energy.

    ### X-Ray Region

    • Fundamental to producing a high-quality radiograph.

    ### Radiofrequency Region

    • Fundamental aspect in Magnetic Resonance Imaging.

    ### Ultrasound

    • The wave of moving molecules.
    • It requires matter.
    • It cannot exist in a vacuum.

    ### Visible Light

    • Described in terms of wavelength, measured in nanometers (nm).
    • Interacts with rods and cones of the eye.
    • Red has the longest wavelength (700 nm) but the shortest frequency.

    Matter

    • Anything that occupies space and has mass.
    • Mass is a distinguishing characteristic of matter measured in kilograms (kg).

    Atoms

    • Atoms are the smallest unit of matter that cannot be broken down by a chemical reaction.

    Energy

    • The ability to do work.
    • Energy can be transformed from one form to another, but it cannot be created or destroyed.
    • Measured in Joules (J).

    Acceleration

    • The rate of change of velocity with time.
    • Measured in meters per second squared (m/s²).
    • Acceleration is velocity divided by time.

    Weight

    • Force on a body as a result of the downward pull of gravity.
    • Measured in Newtons (N) or pounds (lbs).
    • Weight is calculated as mass multiplied by gravitational acceleration (Wt = (m)(g)).

    Momentum

    • The product of mass and velocity.

    Photon

    • The smallest quantity of any type of electromagnetic energy.
    • A photon can be viewed as a bundle of energy travelling through space at the speed of light (3 × 10⁸ m/s).
    • Photons have no mass and no charge.
    • Their waveform is sinusoidal.
    • Photon energy and frequency are directly proportional.

    Quantum

    • A discrete quantity of energy proportional to the frequency of radiation.

    Frequency

    • The rate at which a wave repeats itself.
    • Measured in Hertz (Hz).
    • 1 Hz equates to 1 cycle per second.
    • Frequency is inversely proportional to wavelength.

    Wavelength

    • The distance between two successive crests or troughs of a wave.
    • Represented by the Greek symbol λ (lambda).
    • Wavelength is inversely proportional to frequency.

    Wave Equation

    • Used for both sound and electromagnetic energy.

    X-rays

    • Emitted from the electron cloud.
    • Produced in diagnostic imaging systems.
    • Interact with electrons.
    • Behave as though they are particles.
    • Polyenergetic/heterogenous.

    Gamma Rays

    • Emitted from the nucleus of a radioactive atom.
    • Emitted spontaneously from radioactive material.

    Inverse Square Law

    • States that the intensity of radiation at a location is inversely proportional to the square of the distance from the source of radiation.
    • If the source-to-image distance (SID) is doubled, the density is reduced to 1/4.
    • The distance from the source mainly affects the density of the radiograph.
    • Longer distance/wavelength results in decreased density.

    Max Planck

    • Synthesized our understanding of electromagnetic radiation.
    • Received the Nobel Prize in 1918.

    Particle Model: Max Planck’s Quantum Theory

    • X-rays are identified by their energy (eV) and created with the speed of light (c).
    • The x-ray beam is never below 86% for 12-pulse voltage ripple and never below 96% for high-frequency voltage ripple.

    High Frequency

    • Produces nearly constant potential voltage waveform.
    • Smaller, less costly and more efficient.
    • Improves image quality at a lower patient dose.
    • Requires a 12 kVp reduction.

    Deterministic Radiation Response

    • Acute radiation effect.
    • Death is the most devastating human response to radiation exposure.
    • Three Mile Island incident (1979) and Chernobyl (April 1986).
    • Examples include: Nausea, vomiting, diarrhea, and death.

    Latent Period

    • The time after exposure during which there are no signs of radiation sickness.
    • Approximate: 100-10,000 rad (1-100 Gyt).

    Hematologic Syndrome

    • Characterized by a reduction in white cells, red cells, and platelets.
    • Approximate: 200-1000 rad (2 to 10 Gyt).
    • Mean survival time: 10-60 days.
    • Clinical signs include: Vomiting, diarrhea, anemia, leukopenia, hemorrhage, fever, and infection.
    • Prodomal Period: Mild.
    • Latent Period: General feeling of wellness.
    • Period of Manifest Illness: Vomiting, mild diarrhea, malaise, lethargy, and fever.
    • Recovery: 2-4 weeks or 6 months for full recovery.
    • Cause of Death: Generalized infection, electrolyte imbalance, and dehydration.

    GI Period

    • Occurs because of severe damage to the cells lining the intestines.
    • Approximate Dose: 1000-5000 rad (10 to 50 Gyt).
    • Mean survival time: 4-10 days.
    • Clinical signs: Same as hematologic plus electrolyte imbalance, fatigue, and shock.
    • Prodomal Period: Vomiting and diarrhea.
    • Latent Period: No symptoms present.
    • Period of Manifest Illness: Second wave of nausea and vomiting, followed by diarrhea, and anorexia.
    • Cause of Death: Unprevented rapid progression of symptoms.

    CNS Period

    • Ultimate cause is elevated fluid content of the brain, which leads to increased intracranial pressure, vasculitis, and meningitis.
    • Approximate Dose: Greater than 5000 rad (Greater than 50 Gyt).
    • Mean survival time: 0-3 days.
    • Clinical signs: Same as GI plus ataxia, edema, system vasculitis & meningitis.
    • Prodomal Period: Severe nausea & vomiting.
    • Latent Period: Earlier symptoms disappear.
    • Period of Manifest Illness: More severe prodomal symptoms, disoriented, loss of muscle coordination, dyspnea, convulsive seizures, loss of equilibrium, ataxia & lethargy.

    LD50/60

    • 50% of irradiated subjects die within 60 days.

    Mean Survival Time

    • As the whole-body radiation dose increases, the average time between exposure and death decreases.

    Local Tissue Damage

    • Certain part of the body is being irradiated.
    • Requires higher dose for a response compared to whole-body irradiation.
    • Leads to lack of function of tissues or organs.
    • Atrophy is shrinkage of tissues or organs.

    Skin

    • Limitation of radiation – Orthovoltage xrays (200-300 kVp xrays).
    • Erythema: Sunburn-like reddening of the skin (3-10 Gy).
    • Desquamation: Peeling of the skin (10 Gy).
    • Skin Erythema – Requires to affect 50% of those irradiated (SED50) is about 5 Gyt (500 rad).

    Epilation (Hair loss)

    • Grenz rays (soft xrays) – 10 to 20 kVp

    Effects on Gonads

    • Gonads are highly radiosensitive.
    • 10 rad: Menstrual delay.
    • 200 rad: Temporary infertility.
    • 500 rad: Permanent sterility.
    • 25-50 rad: Increased genetic mutation.
    • 10 rad: Reduced number of spermatozoa.
    • 200 rad: Temporary infertility.
    • 500 rad: Permanent sterility.

    Hematologic Effects

    • 25 rad (250 mGy) measurable hematologic depression.
    • Decreases the number of all types of blood cells.
    • Lethal injury involves a decrease in the number of blood cells.

    Electrification

    • The process of adding or removing electric charge from an object
    • Includes: Contact, friction, and induction.

    Electrostatic Law

    • Like charges repel, unlike charges attract.

    Electrostatics

    • The study of stationary electric charges.
    • Electric charge distribution is uniform throughout or on the surface (Law of Distribution).
    • Electric charge of a conductor is concentrated along the sharpest curvature of the surface (Law of Concentration).

    Electric Potential

    • The amount of work needed to move a unit of positive charge from a reference point to a specific point.
    • Measured in volts (V).

    Diode

    • Tube with two electrodes.

    External Components

    • Used to position and support the x-ray tube.
    • Include the support system and ceiling support system.

    Radiolucent

    • Describes areas of less density.
    • Allows light to pass through.
    • Appears black on a radiograph.
    • Example: Lung tissue.

    Radiopaque

    • Describes areas of more density.
    • Prevents light transmission.
    • Absorbs light.
    • Appears white on a radiograph.
    • Example: Bones.

    Matter

    • Anything that occupies space and has mass
    • Mass is measured in kilograms (kg)

    Atoms

    • The building blocks of matter
    • William Crookes invented the Crookes tube, the forerunner of modern fluorescent lamps and X-ray tubes
    • Barium platinocyanide is a fluorescent material used by Roentgen
    • Fluorescence refers to the emission of visible light only during stimulation

    General Types of X-ray Examination

    • Radiography: Uses X-ray film and a ceiling-mounted X-ray tube to produce fixed images
    • Fluoroscopy: Creates moving images with an X-ray tube and a fluorescent screen
    • X-ray Voltage: Measured in kVp (kilovolts peak), which indicates the quality or penetrating power of the X-ray beam.
    • X-ray Current: Measured in mA (milliamperes), which represents the quantity of X-rays produced.

    History of Radiation Physics

    • 1904: Leonard demonstrated the use of double emulsion film
    • 1904: Clarence Dally became the first X-ray fatality
    • Early 1900s: William Rollins pioneered the use of collimation and filtration in X-ray procedures
    • 1907: H.C. Snook introduced the interrupter less transformer, known as the Snook Transformer
    • 1913: William Coolidge invented the Coolidge X-ray tube
    • 1913: Gustav Bucky invented the stationary grid, also known as the "glitterblende"
    • 1915: Hollis Potter invented the moving grid. The Potter-Bucky (reciprocating grid) was introduced in 1921
    • 1946: The light amplifier was demonstrated at Bell Telephone Laboratories
    • 1950s: The light amplifier was adapted for fluoroscopy
    • 1960s: Diagnostic ultrasound (UTZ) and gamma camera were developed
    • 1970s: Positron Emission Tomography (PET) and Computed Tomography (CT) were introduced
    • 1980s: Magnetic Resonance Imaging (MRI) became an accepted modality. Superconductors were implemented

    Law of Distribution

    • Electric charge distribution is uniform throughout or on the surface
    • The study of electric charge in motion is called electrodynamics

    Conductors

    • Materials that allow electrons to flow easily
    • Require voltage to move electrons
    • Characteristics:
      • Variable resistance
      • Obeys Ohm's Law
    • Examples: Copper, aluminum, and water

    Insulators

    • Substances that do not allow electrons to flow easily
    • Characteristics:
      • Extremely high resistance
      • High voltage is required for insulation
    • Examples: Glass, rubber, and clay

    Semiconductors

    • Materials that sometimes behave like insulators and sometimes like conductors
    • Characteristics:
      • Can be resistive

    Superconductivity

    • Some materials exhibit no resistance below a critical temperature
    • Characteristics:
      • No resistance
      • No electric potential required (voltage)
    • Examples: Niobium and titanium

    Electric Circuits

    • The path of electron flow from the generating source through various components and back again

    Electric Current/Electricity

    • Flow of electrons through a conductor
    • Direction: Always opposite the electron flow
    • Measured in Amperes (A)

    Electric Resistance

    • The opposition to the flow of electric current
    • Measured in Ohms
    • Increased electric resistance results in a reduced electric current

    Ohm's Law

    • Voltage across the total circuit or any portion of the circuit is equal to the current times the resistance
    • Formula: V = I x R

    Alternating Current (AC)

    • Electrons flow alternately in opposite directions
    • Electrons flow first in a positive direction and then in a negative direction
    • Has a sinusoidal wave pattern

    Magnetism

    • Oxide of iron (Fe3O4) is a magnetic material
    • Lodestone or Leading Stone is a rod like stone that moves back and forth
    • Any charged particle in motion creates a magnetic field
    • Magnetic field is created by rotating electrons on their axis, either clockwise or counterclockwise
    • The spin of protons in hydrogen creates nuclear magnetic dipoles, which is the basis of MRI

    Dipolar/Bipolar

    • A magnet with two poles (North and South Pole)

    Diode

    • A tube with two electrodes

    External Components:

    • Support System: Helps the RT position the X-ray tube accordingly
    • Ceiling Support System: Used to adjust the X-ray tube's position

    High Frequency

    • Produces a nearly constant potential voltage waveform
    • Smaller, less costly, more efficient, and produces better image quality with lower patient dose
    • Requires a 12-kVp reduction
    • Example: 100 rad (1 Gyt)

    Deterministic Radiation Response

    • Acute Radiation Effect: Occurs after large doses of radiation delivered over a short time
    • Death: The most devastating human response to radiation exposure
    • Three Mile Island (1979) and Chernobyl (1986): Notable examples of radiation incidents

    Principal Early Effects of Radiation Exposure on Humans and Approximate Threshold Dose

    • Death:
      • Whole body > 200 rad (2 Gyt)
    • Hematologic Depression:
      • Whole body > 25 rad (250 mGy)
    • Skin Erythema:
      • Small Field > 200 rad (2 Gyt)
    • Epilation (Hair Loss):
      • Small Field > 300 rad (3 Gyt)
    • Chromosome Aberration:
      • Whole body > 5 rad (50 mGy)
    • Gonadal Dysfunction:
      • Local Tissue > 10 rad (100 mGy)

    Acute Radiation Syndrome (ARS)

    • Radiation sickness that occurs in humans after a whole-body dose of 1 Gy (100 rad) or more of ionizing radiation delivered over a short time
    • Three Syndromes: Hematologic Death, Gastrointestinal (GI) Death, and CNS Death

    Three Syndromes of ARS

    • Hematologic Syndrome
      • Approximate Dose: 200 - 1000 rad (2 to 10 Gyt)
      • Mean Survival Time: 10-60 days
      • Clinical Signs: Vomiting, diarrhea, anemia, leukopenia, hemorrhage, fever, and infection
    • Gastrointestinal (GI) Syndrome
      • Approximate Dose: 1000-5000 rad (10 to 50 Gyt)
      • Mean Survival Time: 4-10 days
      • Clinical Signs: Same as hematologic syndrome plus electrolyte imbalance, fatigue, and shock
    • CNS Syndrome
      • Approximate Dose: Greater than 5000 rad (Greater than 50 Gyt)
      • Mean Survival Time: 0-3 days
      • Clinical S&S: Same as GI plus ataxia, edema, system vasculitis and meningitis

    LD 50/60

    • Represents a dose that results in death for 50% of irradiated subjects within 60 days

    Mean Survival Time

    • As the whole-body radiation dose increases, the average time between exposure and death decreases

    Local Tissue Damage

    • Occurs when a specific part of the body is irradiated, requiring a higher dose compared to whole-body irradiation
    • Can lead to dysfunction, atrophy, or recovery of the affected organ or tissue

    Skin Effects

    • Skin Erythema: Requires a dose of about 5 Gyt (500 rad) to affect 50% of those irradiated (SED50). It resembles sunburn-like reddening of the skin.
    • Desquamation: Occurs after erythema and refers to the peeling or shedding of the skin.
    • Epilation (Hair Loss): Soft X-rays (10 to 20 kVp), also known as Grenz rays, can cause hair loss.

    Effects on Gonads

    • Gonads are highly radiosensitive
    • 10 rad (100 mGy) : Menstrual delay
    • More than 200 rad (2 Gyt) : Temporary infertility
    • 500 rad (5 Gyt): Permanent sterility
    • 25-50 rad (250-500 mGy): Increased genetic mutation, potentially impacting offspring
    • Testes:
      • 10 rad (100 mGy): Reduced sperm count
      • 200 rad (2 Gyt): Temporary infertility
      • 500 rad (5 Gyt): Permanent sterility

    Hematologic Effects

    • Hematologic depression occurs with 25 rad (250 mGy) of radiation exposure
    • Radiation can decrease the number of all blood cell types, affecting the body's defense mechanisms and oxygen transport
    • Lethal injury may involve damage to the bone marrow.

    Radiation Protection

    • ALARA stands for "As Low As Reasonably Achievable" and is a principle that encourages minimizing radiation exposure.
    • Cardinal Principles for radiation safety are Shielding, Time, and Distance.
    • Shielding involves using materials like lead to absorb radiation.
    • Time refers to minimizing the duration of exposure to radiation.
    • Distance emphasizes staying away from sources of radiation.
    • Filtration removes low-energy x-rays, improving image quality and reducing patient exposure.
    • Collimation restricts the x-ray beam to the area of interest, reducing scatter radiation and improving image contrast.
    • Intensifying Screens reduce patient exposure to x-rays by up to 95%.
    • Protective Apparel like lead-impregnated gloves, shields, and aprons are worn to minimize radiation exposure.
    • Gonadal Shielding is crucial for patients of childbearing age.
    • Protective Barriers are lead-lined to contain radiation and protect staff.
    • Concrete walls should be at least 6 inches thick to adequately block radiation.

    Key Concepts

    • Energy is the ability to do work and can be transformed but not created or destroyed.

    • Newton's Laws of Motion:

      • Law of Inertia: A body at rest remains at rest, and a body in motion stays in motion unless acted upon by an external force.
      • Law of Force: Force equals mass multiplied by acceleration (F=ma).
      • Law of Action/Reaction: For every action, there's an equal and opposite reaction.

    • Heat is the transfer of energy, typically through conduction, convection, and radiation.

    • Acceleration is the rate of change of velocity, measured in meters per second squared (m/s²).

    • Weight is the force exerted on an object due to gravity, calculated as mass multiplied by gravity (Wt = mg).

    • Momentum is the product of mass and velocity, representing the inertia in motion.

    Photons

    • Photons are the smallest units of electromagnetic energy, like tiny bundles of energy traveling at the speed of light.
    • Photons have no mass or charge.
    • They oscillate in a sinusoidal pattern.

    Frequency and Wavelength

    • Frequency is the rate at which a wave oscillates, measured in Hertz (Hz).
    • Wavelength is the distance between two successive crests or troughs of a wave.
    • Frequency and wavelength are inversely proportional.
    • The wave equation describes the relationship between frequency, wavelength, and the speed of light.

    Electromagnetic Spectrum

    • The X-ray region is crucial for creating high-quality radiographs.
    • Radiofrequency is essential for magnetic resonance imaging (MRI).
    • Ultrasound utilizes sound waves that require a medium to travel and cannot exist in a vacuum.
    • Visible Light interacts with the rods and cones in the eye, allowing us to see.
    • Red light has the longest wavelength (700nm) but the shortest frequency.

    Superconductivity

    • Superconductors are materials that conduct electricity with zero resistance when cooled to extremely low temperatures.
    • Superconductivity refers to the property of matter exhibiting zero resistance below a specific temperature.
    • Examples include Niobium and Titanium.

    Electricity

    • Electric circuits are closed loops where electrons flow from a source through components and back.
    • Electric Current is the flow of electrons through a conductor, measured in Amperes (A).
    • Electric Resistance hinders the flow of electrons, measured in ohms.
    • Ohm's Law states that voltage is equal to current multiplied by resistance (V = IR).
    • Alternating Current (AC) involves electrons flowing alternately in opposite directions, creating a sinusoidal wave.

    Magnetism

    • Magnetism is a force caused by moving electric charges.
    • Magnetic fields are created by any moving charged particle.
    • The oxide of iron (Fe3O4) is a naturally occurring magnetic material, known as lodestone.

    History of X-ray

    • Leonard (1904) developed the use of double emulsion film.
    • Clarence Dally (1904) was the first x-ray fatality.
    • William Rollins (Early 1900s) pioneered the use of collimation and filtration in X-ray imaging.
    • H.C. Snook (1907) introduced the interrupterless transformer (Snook Transformer).
    • William Coolidge (1913) introduced the Coolidge x-ray tube.
    • Gustav Bucky (1913) invented the stationary grid also known as "glitterblende".
    • Hollis Potter (1915) invented the moving grid. The Potter Bucky (reciprocating grid) was introduced in 1921.
    • Light Amplifier (1946) was demonstrated at Bell Telephone Laboratories.

    General Types of X-ray Examination

    • Radiography uses X-ray film and a tube mounted from the ceiling to produce fixed images.
    • Fluoroscopy produces moving/dynamic images using a fluoroscopic screen.

    X-ray Parameters

    • X-ray Voltage (kVp) is measured in kVp and determines the quality of the X-rays.
    • X-ray Current (mA) is measured in mA and determines the quantity of X-rays.

    X-ray Protective Measures

    • Leaded walls should contain at least 1.5mm of lead.
    • Radiation detection apparatus should be able to measure radiation exposure levels up to 500 mGya/hr (50R/hr).

    Units of Measurements

    • Physics is the study of the interactions of matter and energy.
    • Base Quantities:
      • Mass
      • Length
      • Time
    • Secondary Quantities: combinations of one or more base quantities.
    • Special Quantities:
      • Exposure dose
      • Equivalent dose
      • Radioactivity

    Energy

    • Energy is the ability to do work.
    • Energy can be transformed from one form to another, but cannot be created or destroyed.
    • The SI unit for energy is the Joule (J).

    Acceleration

    • Acceleration is the rate of change of velocity with time. It is the change in velocity divided by time.
    • The unit for acceleration is meters per second squared (m/s²).

    Weight

    • Weight is the force on a body caused by the downward pull of gravity.
    • Weight = mass x acceleration due to gravity (Wt=(m)(g)).

    Momentum

    • Momentum is the product of mass and velocity.

    Photon

    • The smallest quantity of any type of electromagnetic energy.
    • It travels at the speed of light (3 x 10⁸ m/s).
    • Has no mass and no charge.
    • It has a sinusoidal waveform.
    • Photon energy and frequency are directly proportional.

    Quantum

    • A small bundle of energy associated with electromagnetic radiation.

    Wavelength (λ)

    • The distance between two successive crests or two successive troughs of a wave.
    • Inversely proportional to frequency.

    Wave Equation

    • Used for both sound and electromagnetic energy.

    X-rays

    • Emitted from the electron cloud of an atom.
    • They interact with electrons in materials.
    • X-rays behave as particles and are polyenergetic/heterogeneous.

    Gamma Rays

    • Emitted from the nucleus of a radioactive atom.
    • They are emitted spontaneously from radioactive material.

    Inverse Square Law

    • The intensity of radiation is inversely proportional to the square of the distance from the source of radiation.
    • If the source-to-image distance (SID) is doubled, the density is reduced to 1/4.

    Electromagnetic Radiation

    • Includes X-rays, gamma rays, visible light, ultraviolet light, infrared light, microwaves, and radio waves.
    • Electric and magnetic fields are changing.
    • Characterized by frequency and wavelength.

    X-ray Region

    • Fundamental for producing high-quality radiographs.

    Radiofrequency Region

    • Fundamental aspect in Magnetic Resonance Imaging (MRI).

    Ultrasound

    • The wave of moving molecules.
    • It requires matter and cannot exist in a vacuum.

    Visible Light

    • Described in terms of wavelength.
    • Measured in nanometers (nm).
    • Interacts with rods and cones of the eye.
    • Red has the longest wavelength (700nm) but the shortest frequency.

    Radiolucent

    • Describes areas of less density that transmit light easily.
    • Appears black in the radiograph, e.g., lung tissue.

    Opaque (Opacity)

    • Describes areas of higher density that prevent light transmission.
    • Absorbs light.
    • Appears white in the radiograph, e.g., bones.

    Radiopaque

    • Materials that absorb X-rays, appearing white on the radiograph.

    Max Planck

    • Made significant contributions to the understanding of electromagnetic radiation.
    • Received the Nobel Prize in Physics in 1918.

    Particle Model: Max Planck’s Quantum Theory

    • X-rays are identified by their energy (eV) and created with the speed of light (c).

    NCRP Report #116

    • Formulates and publishes scientifically researched recommendations on radiation protection and measurements in the US.

    Occupational Exposure

    • Annual effective dose limit is 50 mSv.
    • Lens of the eye: 150 mSv
    • Skin, hands, feet: 500 mSv
    • Cumulative Effective Dose (CEfD): Age x 10 mSv.

    Radiation Protection Guidance

    • Inner boundary is established at an exposure rate of 100 mGya/hr (10 R/hr).
    • Outer boundary should be established when exposure exceeds 100 uGya/hr (10 mR/hr).

    Monitoring Devices

    • Optically Stimulated Luminescence (OSL):
      • Uses Aluminum Oxide (Al2O3) chips, which emit blue light when stimulated with green light.
      • The intensity of the emitted blue light is proportional to the radiation exposure received.
      • Typically expressed in units of 5 mrem on the written report.

    Electrostatics

    • The study of stationary electric charge.
    • Electric charge distribution is uniform throughout or on the surface (Law of Distribution).
    • Electric charge of a conductor is concentrated along the sharpest curvature of the surface (Law of Concentration).
    • Like charges repel, unlike charges attract (Inverse Square Law).

    Effective Dose

    • Patient radiation exposure and dose during medical X-ray imaging.
    • Represents the whole-body dose.
    • A weighted average dose to each tissue.
    • Occupational effective dose assumed to be 10 times the monitor dose.

    Radiation Protection

    • ALARA stands for As Low As Reasonably Achievable.
    • Cardinal Principles are Shielding, Time, Distance (STD).
    • Shielding is the use of materials to absorb radiation.
    • Time is the duration of exposure to radiation.
    • Distance is the separation between the source of radiation and the person.

    Filtration

    • Absorbs low-energy x-rays.

    Collimation

    • Restricts the useful x-ray beam.
    • Reduces scatter radiation.
    • Improves image contrast.

    Intensifying Screen

    • Reduces x-ray exposure by more than 95%.

    Protective Apparel

    • Made of lead-impregnated material.
    • Examples include gloves, shields, aprons.

    Gonadal Shielding

    • Used with all persons of childbearing age.

    Protective Barriers

    • Lead-lined with a leaded-glass window.
    • Complete concrete wall is 6 inches thick.

    Basic Radiation Protection

    • Mass is the amount of matter in an object, measured in kilograms.
    • Weight is the force exerted on an object due to gravity, measured in Newtons or pounds.

    Time

    • One second is the vibration of atoms of a cesium atomic clock.

    Derived Quantities

    • Velocity is the rate of change of position over time, measured in meters per second (m/s).
    • Force is a push or pull on an object, measured in Newtons.
    • Heat is the kinetic energy of random motion of molecules, transferred via conduction, convection, and radiation.
    • Work is the force applied over a distance, measured in Joules (J).
    • Power is the rate of doing work, measured in Joules per second (Watts).

    Other Based Quantities

    • Current is the flow of electrical charge, measured in Amperes.
    • Mole is the unit of amount of substance, measuring the size of a molecule.
    • Candela is the unit of luminous intensity, used to measure luminescence.

    Thermal Radiation

    • Activity is the number of nuclear disintegrations per unit time.

    Refraction

    • The deviation of light as it passes from one transparent medium to another.

    Sunlight

    • Contains visible light and two invisible forms of light: infrared and ultraviolet.

    Infrared

    • Has a longer wavelength than visible light.
    • Has a shorter wavelength than microwaves.
    • Heats any substance it shines on, known as radiant heat.

    Ultraviolet

    • Causes sunburn.
    • Lies between visible light and ionizing radiation.
    • Interacts with molecules.

    Electromagnetic Wave Equation

    • c = fλ
    • Where:
      • c is the speed of light (3 x 10^8 m/s)
      • f is the frequency
      • λ is the wavelength

    The Electromagnetic Spectrum

    • A continuum of electromagnetic energy.
    • The acronym "Real Men In Vegas Uses X-Ray Goggles" can be used to remember the spectrum's order: Radio, Microwave, Infrared, Visible light, Ultraviolet, X-rays, Gamma rays.
    • All forms of electromagnetic radiation travel at the speed of light.

    Three Regions Important to Radiologic Science

    • Visible light region (VL) is crucial for viewing radiographic and fluoroscopic images.

    Radiofrequency (RF)

    • Range: 0.3 kHz-300 GHz
    • Range in MRI: 1-100 MHz
    • Low energy, long wavelength.

    Microwaves

    • Very-short wavelength RF
    • Higher than broadcast RF
    • Lower than infrared
    • Interacts with hotdogs and hamburgers.

    Ionizing Radiation

    • Higher energy, lower wavelength
    • Capable of ionization.

    X-rays and Gamma Rays

    • The only forms of ionizing electromagnetic radiation of radiologic interest.
    • Differ in origin: X-rays originate from the electron cloud, while gamma rays originate from the nucleus.

    Health Physics

    • Concerned with providing occupational radiation protection and minimizing radiation dose to the public.
    • A health physicist is a radiation scientist who is concerned with rad safety.
    • ALARA (As Low As Reasonably Achievable) is a guiding principle in radiation protection.
    • Clarence Dally was the first American fatality due to radiation exposure, serving as Thomas Edison’s assistant.
    • The International Commission on Radiological Protection (ICRP) conducts research and provides recommendations on radiation protection worldwide.
    • The National Council on Radiation Protection and Measurements (NCRP) also sets radiation protection standards.

    Wave-Particle Duality

    • Photons interact with matter most easily when the matter is approximately the same size as the photon wavelength.
    • Wave-particle duality: States that both wave and particle concepts must be retained, because wave-like properties are exhibited in some experiments, while particle-like properties are exhibited in others.

    Wave Model: Visible Light

    • The shortest wavelength (violet) extends up until the longest wavelength (red) in the VL spectrum.
    • Visible light is sensed by the human eye.
    • Visible light behaves like a wave.

    Attenuation

    • The reduction of the strength or intensity of x-rays as they pass through matter.
    • The reduction in intensity results from scattering and absorption.

    Lucent (Lucency)

    • Lucent refers to the degree of transparency or the ability of radiation to pass through matter.

    Half Value Layer (HVL)

    • The thickness of material needed to reduce radiation intensity to half its original value.

    Tenth Value Layer (TVL)

    • The thickness of material needed to reduce radiation intensity to one-tenth its original value.

    Time

    • Minimize time: Dose of an individual is directly related to the duration of radiation exposure.

    Distance

    • Increasing the distance between the source of radiation and the person will rapidly decrease radiation exposure.

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    Radiation Physics Cluster 1 PDF

    Description

    Explore the fascinating evolution of X-ray technology through key inventions and milestones from the early 1900s to the 1980s. This quiz covers significant contributors and their inventions that have shaped diagnostic imaging. Test your knowledge on the pioneers who advanced X-ray techniques and medical imaging.

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