X-rays Study Guide - Chapter 1 PDF

Study Guide- Chapter 1 ▪ Who discovered x-rays and when? Wilhelm Conrad Roentgen on November 8th, 1895. ▪ What type of tube was Wilhelm Roentgen experimenting with? Crookes Tube. A glass low vacuum tube. o Understand Crooke’s tube and its design ▪ What type of material was used to pr...

Study Guide- Chapter 1 ▪ Who discovered x-rays and when? Wilhelm Conrad Roentgen on November 8th, 1895. ▪ What type of tube was Wilhelm Roentgen experimenting with? Crookes Tube. A glass low vacuum tube. o Understand Crooke’s tube and its design ▪ What type of material was used to produce the first x-ray? Paper covered with barium platinocyanide. o What is fluorescence and how does it work? Instant production of light from the interaction of some type of energy (xrays) and some element (in this case barium platinocyanide). o How long was the first x-ray exposure of his wife’s hand? 15 minutes. ▪ What was the branch of medicine concerned with the use of x-rays called? Roentgenology. o What was the unit of radiation exposure? Roentgen. ▪ When did Roentgen receive the first Nobel Prize given in physics? 1901. ▪ What does the letter X in x-ray represent? the unknown. ▪ What is erythema? Reddening and burning of the skin. ▪ What is electromagnetic radiation? A form of energy that travels in waves and has both electric and magnetic fields. ▪ What are the properties of x-rays? o Invisible, electrically neutral, have no mass, travel at the speed of light in a vacuum, cannot be focused by a lens, form a polyenergetic (heterogenous) beam, produced in a range of different energies, travel in straight lines, can cause substances to fluoresce (light up), can penetrate human body, can be absorbed or scattered (deflected) in the human body, produce a secondary radiation if absorbed, can cause damage to living tissue. ▪ State the speed of light? 3 x 10*8 m/sec or 186,000 miles ▪ What kind of energy do x-rays possess? kinetic energy ▪ What is electrical energy applied to the tube converted to? heat and x-rays. ▪ How is the maximum energy of an x-ray photon expressed? Kilovoltage Peak (kVp). ▪ What is the medically useful diagnostic range of x-ray energies? 30kVp to 150kVp. ▪ What is the dual nature of x-ray energy? They behave like waves and particles. ▪ What is wavelength? The distance between two crests or troughs. o What are the two units of measurement for wavelength? Angstroms (Å) and nanometer (nm). o What is an Angstrom (Å)? A metric unit of length equal to one ten-billionth of a meter, or 10^-10 m. o What is the range of wavelength of x-rays? 0.1 to 1.0 Å. o What is the Greek letter that represents lambda? (λ) this is the letter that represents wavelength in the formula. ▪ What is frequency? The number of waves (cycles) that pass through a given point per unit of time (second). o What is the unit of measurement of frequency? Hertz (Hz). o What is one Hertz equal to? One cycle per second. o What is the Greek letter that represents nu? (v) also a lower case (f). These two letters represent frenquency in the formula. ▪ What is the relationship between wavelength and frequency? Inverse. o What happens to frequency if wavelength decreases and vice versa? Frequency increases when wavelength decreases. ▪ What is amplitude? The height of a wave. ▪ What is a photon or quantum? Small, discrete bundle of energy. o How is the energy of an individual photon measured? Electronvolts (eV). ▪ What are the two systems used for quantifying radiation exposure? Standard (British) and International System (SI). o Which of the two is more widely adopted? The SI system. o Why do we quantify radiation? To understand radiation exposure, dose, and biologic effects. o Define Exposure and its units of measure (refer to table and chapter) o Define Air Kerma and its units of measure (refer to table and chapter) o Define Absorbed Dose and its units of measure (refer to table and chapter) o Define Equivalent Dose and its units of measure (refer to table and chapter) how is Equivalent dose calculated? Absorbed dose * Wr o Define Effective Dose and its units of measure (refer to table and chapter) How is effective dose calculated? Absorbed dose * Wr * Wt  o Define Radioactivity and its units of measure (refer to table and chapter) ▪ What does ALARA and ORP stand for? As Low As Reasonably Achievable and Optimization for Radiological Protection ▪ What are the cardinal principles for minimizing radiation dose? Time, distance, shielding ▪ What is a radiation weighting factor? A quality factor takes into account the biologic effects produced by a certain type of radiation. o How is radiation weight factor expressed? Wr o What is the weight factor for x-rays and gamma rays? 1 ▪ What is a tissue weighting factor? A correcting factor that takes into account the radiosensitivity of different tissues in the body. Some tissues are more easily harm by radiation than others. o How is the tissue weighting factor expressed? Wt