Radiography Chapter 1

Chapter 1

• X-rays were discovered by Roentgen in 1895.
• Radiographs is the proper term for "pictures" produced by X-rays.
• The American Society of Radiologic Technologists (ASRT) is the world's oldest and largest radiologic science professional organization.
• The American Registry of Radiologic Technologists (ARRT) establishes standards and provides certification examinations for radiologic technologists.
• RT (R) stands for Registered Technologist (Radiography).
• JRCERT is the national organization that formally conducts accreditation of education programs in radiologic technology.
• Fluoroscopy provides real-time viewing of X-ray images in motion.
• To determine the credentials needed to practice limited radiography, contact the State Department of Health.
• Limited radiography is called limited because the scope of practice is limited.
• Within the scope of practice for a limited operator are basic radiographic examination and explanation of procedures.
• Angiography is an imaging modality that uses contrast media to image blood vessels.
• Consequences for practicing beyond the scope of practice of a limited operator may include monetary fines, revocation of license/permit, and imprisonment.
• Reciprocity means credentials issued in one state are recognized in another state.
• Performing mammograms in a private physician's office qualifies as practicing beyond the scope of a limited operator.
• X-ray examinations are performed on orders issued by physicians.
• Explaining the procedure and the preparation to the patient is considered a duty of a limited X-ray machine operator.
• A medical doctor who diagnoses treats disorders and diseases of the feet is a podiatrist.
• JRCERT began to accredit limited scope X-ray machine operator educational programs.
• A limited X-ray machine operator is the nationally accepted and most often used term for the limited X-ray operator.
• Bone densitometry is the specialized area of radiology that uses X-rays to measure the bone mineral content and density of bones.

Chapter 2

• X-rays exit the X-ray tube via the tube port.
• The control booth is the portion of the X-ray room that is protected from scatter radiation and is safe during exposures.
• The central ray is a line in the center of the X-ray beam and perpendicular to the long axis of the X-ray tube.
• A latent image is an unseen image on an Image Receptor (IR) that has been exposed to a body part but not yet processed.
• Tissues with greater mass, will absorb more radiation, relative to less dense tissues.
• Attenuation is the absorption of X-rays by matter.
• Scatter radiation has less energy than the primary beam.
• Remnant radiation is the varying intensity of radiation that exits the patient and reaches the IR.
• A cassette and phosphor imaging plate usually comprise the image receptor (IR).
• Primary radiation exits the X-ray tube and travels in air to the patient.
• In computed radiography (CR), images are originally obtained and stored in a phosphor material.
• A collimator varies the radiation field size, and is attached under the tube housing.
• A grid or Bucky is a device to protect the IR from being fogged by scatter radiation.
• The patient is the principle source of scatter radiation.
• A tilting table will allow the head end to be lowered at least 15 degrees into the Trendelenburg position.
• Scattered radiation is primary radiation that enters the patient, then leaves the patient traveling in all directions.
• Scatter radiation fog is unwanted image exposure caused by scatter radiation.
• After an X-ray is taken, the image stored in the computed radiography plate needs to be processed in the Image reader device.
• Falling is the most frequent adverse incident that can happen to a patient in the radiology department.
• Detent is a mechanism that tends to stop a moving part in a specific location.

Chapter 3

• The formula used to change mAs to maintain a constant intensity when distance (SID) changes is: mAs 1 / mAs 2 = (SID1)2 / (SID2)2.
• With 400 mA and a 0.5 second exposure time, the mAs is 200.
• A satisfactory AP shoulder radiograph made on a patient measuring 12 cm using 70 kVp will be most similar to a radiograph of a 16 cm patient using 78 kVp.
• To produce a similar radiographic density to a lateral lumbar spine radiograph taken using 120 mAs and 40 inches SID, an SID increase to 60 inches requires the technique to be changed to 270 mAs.
• To compensate for a 2-cm increase in patient part size, adjust the mAs by multiplying it by 1.3 (30%).
• To produce a radiograph of similar density to a satisfactory AP lumbar spine radiograph made using 50 mAs and 78 kVp, while providing less contrast and less exposure to the patient, technique changes using the 15% rule would be 25 mAs, 90 kVp.
• Using 300 mA and 0.02 seconds, the mAs is 6.
• Doubling the SID reduces the intensity of radiation in the radiation field by a factor of 4.
• To produce a similar radiograph to one made using 100 mA and 0.2 seconds, using 400 mA requires 0.05 sec exposure time.
• To produce a similar result to a satisfactory radiograph made using 60 mAs and 72 inch SID at 40 inches SID, the technique is 18 mAs.
• To produce a similar mAs to an image made using 200 mA and 0.05 sec, a similar exposure would be 400 mA and 0.025 sec.
• 3 kVp/cm compensates for patient size changes when kVp is greater than 85.

Chapter 4

• Atoms are the building blocks of all matter.
• The K shell in an atom contains the least number of electrons.
• Electrons are located in an orbit around the nucleus of an atom.
• A proton has a positive charge.
• The K shell in the atom is most important in the production of X-rays.
• When an electron is removed from an atom, the atom is ionized.
• The K electron shell in the atom has the greatest binding energy.
• The number of protons represents the atomic number of an atom.
• Wavelength represents the distance from one crest to the next in a sine wave.
• The frequency of a sine wave is measured by the number of times per second that a crest passes a given point.
• X-rays have the shortest wavelength of the types of electromagnetic energy.
• X-rays penetrate matter.
• All electromagnetic energy moves through space at the same velocity.
• A photon is the smallest possible unit of electromagnetic energy.
• Current applies to the quantity of electrons flowing through a circuit.
• Potential difference refers to the force or strength of the electron flow in the current.
• The ampere is the unit used to measure the rate or volume of current flow.
• The volt is the unit of potential difference.
• Standard voltage provided by utility companies for household use is 120 volts.
• In radiology, 80,000 volts is converted to 80 kVp.
• Milliamperage used in radiology is from 25 to 500.
• High-frequency generators in radiology can use up to 6,000 Hz of electrical frequency.
• Direct current flows in only one direction.
• The frequency of alternating current delivered by electrical utilities in the United States and Canada is 60 Hz.
• A transformer increases or decreases voltage.
• A step-down transformer would have more windings on the primary side.
• With a 500:1 ratio, a step-up transformer with 100 V across the primary side would have 50,000 V on the secondary side.
• Tungsten is one of the most important elements in radiology.
• Electromagnetic X-rays have short wavelengths and high frequency.
• Rectification is the process of converting alternating current into direct current for X-ray production.
• Electricity is produced when a magnet is moved around a conductor (or the conductor is moved around the magnet); this process is called electromagnetic induction.

Chapter 5

• Pyrex glass comprises the X-ray tube inside the protective house.
• The four essential elements needed for X-ray production: a target, a vacuum, an electron source, and a high potential difference.
• The filament of an X-ray tube is made of a coil of tungsten wire.
• The target of the X-ray tube is made of tungsten.
• A filter removes long-wavelength (low energy) radiation from the primary beam.
• Space charge is the electron cloud that surrounds the hot cathode.
• Free electrons at the cathode for X-ray production come from the filament.
• Thermionic emission is the principle when tungsten atoms are heated, thus their outermost electrons are moved out of the atom in space.
• The anode is positively charged.
• The cathode is negatively charged.
• Most X-ray tubes in use today have a standard rotation speed of 3,600 rpm.
• A high-speed rotating anode allows more efficient heat dissipation.
• The greatest portion of the X-ray beam is made up of bremsstrahlung radiation.
• A high potential difference is required to move the electron stream rapidly across the X-ray tube.
• of the energy applied to an X-ray tube is converted into heat.
• Bremsstrahlung radiation occurs in the anode by the sudden slowing and directional change of an incoming electron.
• Characteristic radiation results from an incoming electron interacting with the K-shell electron in the tungsten atom.
• The degree of angulation of the X-ray tube target will determine the effective focal spot.
• A smaller effective focal spot produces greater image sharpness.
• A larger actual focal spot produces greater tube heat capacity.
• The anode heel effect is a phenomenon of X-ray production resulting in an uneven distribution of radiation within the field.
• The penetrating power of the X-ray beam is controlled by varying the kilovoltage.
• The current across the X-ray tube is measured in units of milliamperes.
• The mAs used for an exposure determines the quantity of radiation in the exposure.
• With 400 mA and 0.02 sec, the mAs is 8.
• When exposure time is very short, the time is usually measured in milliseconds.
• An exposure time measured in 35 milliseconds is 0.035 seconds.
• The heterogeneous X-ray beam is made up of many different energy X-rays.
• Tungsten has a high melting point.
• X-ray equipment capable of producing 70 kVp or more must have 2.5 mm Al eq. equivalent aluminum filtration.
• The primary advantage of X-ray beam filtration lowers patient dose.
• A steeper target angle provides a smaller effective focal spot.
• Filtration decreases the average wavelength of the X-ray beam.
• The precise area on the target where electrons strike is the focal spot.
• The electromagnetic induction motor rotates the anode.
• The X-ray intensity (or volume of X-rays) is 75% greater on the cathode side compared to the anode side of the X-ray beam.
• mAs primarily controls the density of the radiographic image.
• kVp controls the contrast of the radiographic image.
• Aluminum is used as added filtration in the X-ray tube.

Chapter 6

• The X-ray circuit is divided into the low-voltage, filament and high-voltage circuits.
• The autotransformer is primarily used for variable kVp selection.
• The power to the X-ray room is usually 220 V.
• The mA control on the X-ray generator adjusts the heat for the filament in the X-ray tube.
• The filament circuit supplies the filament with heat for thermionic emission to occur.
• Step-down transformers reduce the voltage on the secondary side to provide an appropriate current to heat the filament.
• Exposure times that are as low as 0.001 sec are typical of an electronic timer.
• Rectification is the process of changing alternating current to direct current.
• The purpose of a diode in an X-ray circuit is to electronically convert AC to DC.
• The X-ray tube is located on the high-voltage side of the X-ray circuit.
• High-frequency generators produce X-rays more efficiently compared to 1-phase and 3-phase generators.
• A series of warm-up exposures is made on a cold X-ray tube to prevent damage to the anode from sudden heating.
• To prolong X-ray tube life, the tubes should be operated at about 80% of capacity.
• The maximum heat capacity of the anode of the tube is rated in terms of heat units.
• mA x time x 1.35 is the formula used to calculate the heat produced by an exposure made on a 3-phase generator.
• Nearly all new x-ray machines manufactured today use high frequency generators.
• In a high-frequency generator, the incoming 60 Hz electrical frequency is raised to 6,000 Hz.
• Automatic exposure control electrical system and device terminates the exposure time after an exact amount of radiation for a given body part has been detected.
• Anatomically programmed radiography (APR) is when some X-ray generators are programmable and the exposure factors from the technique chart can be programmed into the generator.
• When using automatic exposure control (AEC) for setting exposure techniques, exposure time does not have to be set.
• Public law 90-602 states that generators must terminate the exposure at 600 mAs.
• Accurate patient positioning is essential when using AEC for exposure technique.
• If the automatic exposure system fails during an exposure, the back up timer will terminate the exposure.
• The density control override on the X-ray generator enables the operator to override the AEC system when an exposure is overexposed or underexposed.
• APR is the exposure technique system for which a technique chart would not be necessary.
• High frequency X-ray generators will produce the greatest amount of heat for the same exposure technique.
• The X-ray tube capacity for a single exposure can be determined by consulting the tube rating chart.

Chapter 7

• The prime factors of exposure in radiography are milliamperage, exposure time, kilovoltage and distance (SID).
• mAs, is the unit used to indicate the total quantity of X-rays in an exposure.
• When two exposures are made using the following technical factors: Image A: 500 mA, 0.05 seconds, 72 kVp or Image B: 200 mA, 0.125 seconds, 72 kVp, Image A and B would exhibit equal density.
• If the radiographic image is overexposed, decrease mAs to correct the problem.
• The Inverse Square Law expresses the relationship between SID and X-ray beam intensity.
• Intensity and distance are related through the Inverse Square Law.
• The intensity of the X-ray beam is inversely proportional to the square of the distance.
• Density, contrast, distortion, and spatial resolution (detail) are the four primary aspects of radiographic quality.
• Density refers to the overall darkness, or blackness, within a radiographic image.
• Tissue density refers to the mass density of the radiographic subject.
• The primary controlling factor of radiographic density is mAs.
• Radiographic contrast is the difference in density between any two adjacent portions of the image.
• Kilovoltage is the primary controlling factor of contrast.
• An image that demonstrates only a few densities, with a great difference between the densities, is described as having short scale contrast.
• A low kVp setting produces an image with a short scale of contrast.
• Higher kVp settings produce images with a long scale contrast.
• High contrast is most desirable when it is necessary to differentiate tissues with similar tissue densities.
• Fog is generalized unwanted exposure on the image.
• Fog affects radiographic quality by causing decreased contrast.
• Distortion is a variation in the size or shape of the image as compared with the subject it represents.
• Magnification is another name for size distortion.
• Object-image receptor distance (OID) is the distance between the subject or part and the IR.
• The unsharp, “fuzzy” appearance of margins of anatomic structures within the radiographic image is called penumbra.
• Decreased resolution results from a change from the small focal spot to the large focal spot.
• With a large OID, excessive magnification can be reduced by increasing the SID.
• An increased OID will increase magnification.
• Motion of the patient, the tube, or the IR during the exposure results in decreased resolution.
• If the radiographic image appears blurred, spatial resolution is affected.
• The principle means of controlling involuntary motion is to decrease exposure time.
• Quantum mottle or graininess in the radiographic image (due to too few photons interacting with the body part), affects image quality by decreasing spatial resolution.
• Quantum mottle occurs when the mAs or kVp is set too low.
• Communicate with the patient about the procedure and what the patient needs to do to help prevent patient motion.
• Magnification decreases resolution.
• Doubling the mA doubles the quantity of the exposure.
• Contrast is key to the visibility of detail.
• Doubling the mA, doubles the dose to the patient.
• KvP is the primary controlling factor of penetration of X-rays.
• Brightness replaces density in the digital imaging environment.
• Scattered radiation primarily causes fog.
• Unequal magnification of the actual shape of the structure results in shape distortion.
• Foreshortening is when a body part appears on a radiograph as shorter than it actually is.
• Elongation is when a body part appears on a radiograph as longer than it actually is.
• High contrast is what describes an image that demonstrates great differences between the densities.

Chapter 8

• A cassette-based digital imaging system is termed computed radiography (CR).
• Indirect conversion DR systems require 2 steps.
• A PACS system views and stores digital X-ray images.
• The front of an imaging plate is made of a radiolucent material that does not absorb X-rays.
• Barium fluorohalide with europium is used as the phosphor that absorbs the X-ray energy in the imaging plate.
• A laser beam scans the phosphor of a CR plate when it is inserted into the reader for processing.
• In indirect conversion DR systems, a photodiode converts the light in the flat panel detector to an X-ray signal.
• One of the main advantages of using CR and DR digital systems is the ability to process images very fast.
• An exposure technique chart must be used with digital-based X-ray processors to ensure the ALARA concept is practiced.
• Quantum mottle occurs in digital images if there are not enough photons reaching the IR.
• Compensating filters should be used when imaging body parts that have extreme differences in tissue thickness.
• When splitting a CR cassette in half for two exposures, cover the half not being exposed with lead.
• When using digital systems, the part must be placed in the center of the plate or detector.
• The storage phosphors in the CR plate are hypersensitive to small levels of scatter radiation exposure.
• The collimated X-ray beam should show on a minimum of 2 sides of the IR and image.
• Grids are important when using digital systems for mobile radiography.
• The phosphor is exposed to white light to erase the anatomical image after the imaging plate is scanned in the CR reader and the image is sent to storage.
• A charge-coupled device (CCD) is used in an indirect conversion DR system to convert light into an electric signal.
• A matrix is a viewing monitor's active viewing area.
• A pixel is each square picture element in a digital viewing monitor.
• Spatial resolution is the amount of detail or sharpness in the digital image.
• Of the matrix sizes, 3,000 x 3,000 matrix produces the best spatial resolution.
• The greatest spatial resolution will be produced when the matrix is large, and the pixels are small.
• A matrix of 1,200 x 1,800 will show 2,160,000 pixels on the viewing monitor.
• Contrast resolution is the ability to distinguish anatomical structures of similar subject contrast.
• Dynamic range is the number of gray shades that a digital system can reproduce.
• Signal-to-noise ratio (SNR) is the ability of the digital system to convert the X-ray input electric signal into a radiographic image.
• Quantum mottle is radiographic image noise, that is not useful in the radiographic image.
• The best quality radiographic image will be produced on the viewing monitor when there is high SNR and low noise.
• Window level controls the density, or brightness, in the radiographic image.
• Window width controls the contrast aspect of the radiographic image.
• Shuttering can blacken the clear or white areas around the collimation edges of a radiograph on the viewing station.
• Image stitching allows separate radiographic images tied into one image for viewing.
• Never electronically put R and L markers through computer software onto the radiographic image.
• Image annotation is the computer software function that allows any type of text to be written on a radiographic image.
• Edge enhancement processing technique increases contrast and sharpens the image.
• A critical step when setting the exposure factors when using digital systems is ensuring the kVp is set correctly.
• The exposure indicator number tells the operator that the correct exposure has been received by the phosphors in the imaging plate.
• The post processing software function allows adjustment of the radiographic image after it has been processed.
• DICOM, (Digital Imaging and Communications in Medicine) universally accepted standard exchanges radiographic images inside and outside the institution, among all manufacturers,.
• DICOM gray-scale function is the term for calibrating an image display system ensuring radiographic images' gray scales are presented consistently.
• Health Level-7 (HL7) effectively ensures all the different information systems within a given hospital or clinic communicate.
• Inadequate exposure technique will cause quantum mottle in the radiographic image.
• The Moire pattern artifact occurs when grid lines are not aligned with the CR reader's laser light.
• Light spots are shown when a foreign matter exists inside the CR imaging plate.
• Phantom or ghost images can appear if the CR imaging plate is not erased properly.
• Fogging occurs when a CR imaging plate receives too much background or scatter radiation.
• PACS system stores, retrieves, sends, and views digital radiographic images extensively managing the image.
• A CR plate inside the cassette, exposed to light for 15 seconds will start to erase.

Chapter 9

• Interactions that produce scatter radiation occur primarily in the patient.
• Compton scatter occurs when an X-ray photon interacts with an outer orbital electron in the patient's body.
• A scattered photon has less energy than the incoming primary beam photon.
• Compton interactions occur at 40 to 125 kVp, which is the entire diagnostic range.
• The photoelectric effect occurs when an incoming photon from the primary beam interacts with an inner shell electron in a patient's body.
• Scatter radiation decreases contrast, thus affecting the radiographic appearance.
• Scatter radiation fog increases as the size of the X-ray field increases.
• Scatter radiation fog will increase if the body part is thicker or larger.
• If the kVp increases, scatter radiation fog increases.
• Scatter radiation fog reduces the visibility of detail in an image by decreasing contrast.
• Reduce scatter radiation fog on a radiograph by using a grid.
• A grid is placed between the patient and the IR, and absorbs scatter radiation.
• Backscatter is Compton scatter that is directed from the patient back toward the X-ray tube.
• Compared to an 8:1 grid, a 12:1 ratio grid will require more exposure to make a satisfactory radiograph.
• Grid frequency is the number of lead strips per inch.
• Grid cutoff is the radiographic appearance of decreased density on the lateral margins of the image.
• Use a grid when the part thickness is greater than 10cm.
• Focused grids have their lead strips aligned to coincide with the primary beam angle.
• Grid cut off results from a grid being misaligned with the central ray causing a light area on the side of the image.
• The grid oscillates preventing the lead strips in the grid from being seen on a radiograph.
• During the photoelectric effect, an incoming photon interacts with the atom in the patient's body and is totally absorbed by the atom.
• Compton interactions will increase as kVp is increased.
• Photoelectric effect interaction will decrease as kVp is increased.
• Collimator template and beam alignment cylinder checks the collimator and beam alignment of the overhead tube crane.
• During the beam alignment test, the X-ray tube must be within 1 degree(s) of perpendicular to be in control.

Chapter 10

• Technique charts are either variable kVp or fixed kVp.
• The technique chart is a detailed list of the radiographic examinations performed in a radiographic room, along with all the exposure factors.
• Technique charts apply to each unique X-ray machine and facility.
• Technique charts need the measurement of patient-body part using an X-ray caliper, expressing the measurement in centimeters.
• A radiographic phantom replicates a human skeleton or part of a skeleton encased in plastic emulating human tissue.
• The Joint Commission requires that technique charts are posted for every radiographic room.
• Technique charts depends on the thickness of the body part to be radiographed.
• Specific mAs value for each projection with small kVp changes to compensate for variances of patient or part size is seen in the variable kVp technique chart.
• The highest kVp setting, the lowest patient dose, and the greatest exposure latitude is seen with the optimum kVp approach to technique charts.
• Using the principle of optimum kilovoltage to formulate exposure techniques will result in the least patient exposure and wide exposure latitude.
• Compared to the variable kVp technique chart, optimal image contrast is lower, for greater detail visibility.
• Determine if the mA station is obtainable at the desired kVp without exceeding the capacity of the X-ray tube by consulting the tube rating chart.
• Using the highest available mA station with a given amount of mAs keeps the exposure time as short as possible.
• Using a low mA station with a given amount of mAs uses the small focal spot.
• To have an exposure time for 50 mAs, with a 200 mA station; use 0.25 seconds.
• kVp level not optimum to penetrate the part cause technique chart failure.
• increasing part size increases the necessary mAs.
• A satisfactory radiograph made using 20 mAs with SID of 40 inches needs an mAs of 45 to produce a similar radiograph with SID of 60 inches.
• A radiograph of too much contrast indicates set, kVp level set too low.
• Cardiomegaly causes increases in exposure technique.
• Bowel obstruction causes decreases in exposure technique.
• When a image is too light, Increase mAs 100%.
• mAs is used if there are radiographic density errors.
• kVp is used if there are alterations to radiographic contrast.
• Contrast is primarily affected by kVp.
• Following the 15% rule when kVp is increased, an 80 kVp exposure technique will be changed to 92 kVp.
• AP Thoracic Spine body projections can benefit from compensating filters.
• Pediatric, patient categories seldom requires for compensating filters for general radiographic examinations.
• A mAs change of 30% will prompt slight, visible changes.
• Degenerative arthritis decreases necessary exposure techniques.
• The main limitation in obtaining images of obese patients is inadequate penetration of the body part.
• Radiographing obese patients require greater kVp.

Chapter 11

• The SI unit for measuring absorbed dose is the gray.
• Air kerma is the SI unit of exposure that measures radiation in air.
• Sievert is the unit of the SI system used to measure equivalent dose.
• The unit commonly used to report the effective dose to occupational workers in the United States is mSv (old mrem).
• The cumulative effective dose ensures that the lifetime risk of occupationally exposed persons remains within acceptable limits.
• Equivalent dose is measured based on the type and energy of radiation exposed.
• The radiation weighting factor for x-ray photons is 1.
• In radiography, patient dose is usually calculated at the skin level.
• The pelvis is the radiographic examination that typically delivers the greatest gonadal exposure.
• According to the Law of Bergonie and Tribondeau, blood and blood is a very radiosensitive type of cells.
• Entrance skin exposure (ESE) are patient doses in radiography.
• Blood changes can be seen at 0.25 Sv, a whole body equivalent dose.
• Nerve cells would not be as vulnerable to x-rays.
• 6.0 Sv is the whole-body equivalent dose that will cause death.
• Short-term effects of radiation would occur within 3 months.
• According to the Law of Bergonie and Tribondeau, adults groups, would not be as sensitive to radiation.
• Erythema is reddening of the skin.
• ALARA serves as the guiding philosophy of radiation protection.
• The EDE limit for whole body dose of occupational radiation exposure for non-pregnant workers older than age 18 who are involved in radiation use is 5.0 rem per year.
• Gonad shields reduce the likelihood of genetic radiation effects.
• Erythema is a common observable short-term effects of radiation.
• LD 50/30 is how the lethal dose of radiation is expressed.
• Lumbar spine radiographic examinations would give the fetus the highest fetal dose.
• The greatest percentage of long-term effects from radiation exposure will occur at 10 to 15 years.
• Erythema is a short-term effect of radiation exposure.
• Short term effects of radiation exposure are predictable.
• Radiation exposure to the gonads causes mutations (changes in the genes of the irradiated person).
• Leukemia would not be a mutation as a result of radiation to the gonads.
• The average American is exposed to 6.3 mSv of annual radiation dose.
• Repeat exposures are the greatest cause of unnecessary radiation to patients.
• The lead-equivalent thickness of a gonad shield should be 0.5 mm.
• Whenever the edge of the radiation field is within 5 cm of the gonads, use a gonad shield.
• The federal regulation for the lead-equivalency of aprons worn in the radiographic room is 0.5 mm.
• The federal regulation for the lead-equivalency of gloves worn during radiographic procedures is 0.25 mm.
• Personnel monitors should be worn whenever radiation workers are likely to risk receiving 10% or more of the annual effective dose limit.
• Optically stimulated luminescence (OSL) is the most widely used and most accurate personnel monitor.
• A personnel monitor cannot measure exposure less than 0.05 mSv.
• Personnel monitors should be worn on the collar outside the apron.
• The National Council on Radiation Protection (NCRP) prepares the standards for radiation dose limits of occupational radiation workers.
• The annual effective dose limit for an occupational radiation worker is 50 mSv.
• A 28 year-old radiation worker can have an annual cumulative effective dose of 280 mSv.
• Greatest risk for a pregnant woman who receives a high exposure is during the first trimester.
• NCRP recommended monthly equivalent dose limit for a pregnant worker is 0.5 mSv.
• The NCRP recommended 9-month equivalent dose limit for a pregnant worker is 5 mSv.
• A declared pregnant radiation worker should wear a second personnel monitor at the waist level.

Chapter 12

• Connective tissue is the most widely distributed and has the greatest variety of form and function.
• Alimentary canal may be used in place of the gastrointestinal tract.
• The two basic divisions of the skeletal system are axial and appendicular.
• A flat bone is made up of two layers of compact bone, with a thin cancellous layer between them.
• A condyle is a rounded process that forms a part of a joint.
• A styloid process is a long, sharp bony process.
• A foramen is a hole in bone that provides a passage for nerves and blood vessels.
• Synarthrosis describes joints that are not moveable.
• Diarthrodial joints are freely moveable.
• Abduction describes moving a body part away from the central axis of the body.
• Extension describes a straightened joint.
• Supination means turning the arm so the palm of the hand is up.
• Anatomic position means standing facing the observer with palms of hands turned forward and toes facing anteriorly.
• Cephalad means toward the head.
• Posterior means the back portion of the body or part.
• The midsagittal plane divides the body into equal right and left halves.
• The midcoronal plane divides the body into equal anterior and posterior halves.
• Supine indicates patient is lying on his or her back.
• If the patient is imaged in the prone position, the patient must be placed in recumbent position on his or her stomach.
• Decubitus imaging position requires a recumbent body position and a horizontal CR.
• Projection describes the path of the CR from the radiographic tube through the patient, and to the IR.
• An axial projection of the spine is achieved when the CR is angled longitudinally more than 10 degrees.
• Three items must be precisely aligned in radiography: the x-ray tube, the IR, and the body part.
• A side marker indicates the side of the patient.
• Blurring of the radiograph image is the result of imaging patient motion.
• A localized area of destructive change in body tissue is called a lesion.
• Symptoms describe the patient's report of his or her perception of the condition.
• Acute conditions are diseases characterized by a sudden onset of symptoms and/or signs.
• latrogenic diseases occur as a result of treatment by health professionals.
• Swelling medical term is edema.

Chapter 13

• Phalanges comprise the digits of the hands.
• Metacarpals are the bones located in the palm of the hand.
• The Scaphoid carpal bone is located in the proximal row on the lateral side.
• The Trapezium carpal bone articulates with the first metacarpal.
• The Ulna bone of the forearm is located on the medial side.
• The radial tuberosity is located at the proximal end, distal to the head of the radius
• The olecranon process is located at the proximal end of the Ulna.
• The styloid process is located at the distal end of the radius.
• The capitulum articulates with the radial head portion of the humerus.
• The acromion is the large, rounded projection that can be felt on the superior, lateral surface of the shoulder.
• For a PA projection, the anterior (palmar) surface of the hand should be in contact with the IR.
• The CR is directed perpendicular to the third MCP joint on the PA projection of the hand.
• Use supportive stair-step sponge strategies if you need to better demonstrate the interphalangeal joints on the PA oblique projection of the hand.
• In radiographing the fingers, anatomy included should be the distal portion of the metacarpals and all of the phalanges
• The medial surface of the hand should be in contact with the IR for a lateral projection of the fifth digit.
• The proximal interphalangeal joint is where the CR is directed for the PA projection of the second digit.
• For the AP projection of the thumb, the MCP joint is the CR direction.
• The thumb should be in the oblique position on a PA projection of the hand.
• PA results in a more magnified image compared to other thumb projection, due to an increase in OID.
• Flexing the fingers into a loose fist places the wrist close to the IR for the PA projection of the wrist.
• When doing the PA oblique axial projection, place coronal plane of wrist at 45-degree angle to IR with anteromedial surface on IR position.
• The lunate and pisiform is best demonstrated on an AP oblique projection of the wrist in medial rotation.
• It is important to include both bones in their entirety and their articulations in radiography of the forearm.
• The proper patient position for the AP projection of the forearm is with the elbow extended, wrist and elbow parallel to IR, hand supinated.
• When radiographing the forearm in a lateral position, make sure the medial surface is in contact with the IR
• AP projection of the proximal forearm and AP projection of the distal humerus is the elbow positioning methods to use if a routine AP projection will not work.
• AP oblique projection and 45-degree lateral rotation position demonstrates the radial head and capitulum without superimposition.
• coronoid process of the ulna and the trochlea elbow anatomy that is best demonstrated on the AP oblique