LRA 211 Radiographic Image Production and Exposure - final study review- Chapters 2, 3, 5,, Exams of Biology

Download LRA 211 Radiographic Image Production and Exposure - final study review- Chapters 2, 3, 5, and more Exams Biology in PDF only on Docsity! LRA 211 Radiographic Image Production and Exposure - final study review- Chapters 2, 3, 5, 6, 7, 8, 9 Which of the following is considered a nucleon? Proton What is the maximum number of electrons permitted in the M shell? 18 Previous Play Next Rewind 10 seconds Move forward 10 seconds Unmute 0:05 / 0:15 Full screen Brainpower Read More What is the maximum number of electrons that will occupy the outermost shell of an atom? 8 We have an expert-written solution to this problem! The purpose of the line focus principle is to create which of the following? large actual and small effective focal spot size The earliest atomic theory based on an arrangement similar to the solar system is attributed to Bohr The three fundamental particles of the atom are the neutron, proton, electron The atomic nucleus contains protons and neutrons The component of the nucleus that has a positive charge and mass is the Proton The electron shell closest to the nucleus is lettered K Which of the following is not part of the electromagnetic spectrum? sound Which of the following electromagnetic radiations have the lowest energy level? radiowaves As the wave's frequency increases, the wavelength decreases Frequency is typically measured in hertz The process of removing an electron from an atom is ionization X-rays are produced using fast moving electrons Which of the following helps to keep the x- ray tube cool on the inside of the protective housing? cooling fans and an oil bath In terms of the x-ray tube, envelope is another name for the glass or metal enclosure The positive end of the x-ray tube is the anode The negative end of the x-ray tube is the cathode The area of the envelope where x-rays should exit the tube is the target window The anode serves as a(n) target for the electron interaction to produce x-ray. electrical conductor. heat conductor. The two types of anode designs are stationary and rotating Tungsten is used to coat the anode disc because it has a high atomic number With a rotating anode, the focal spot becomes a focal track A filament electron interacts with an outer- shell electron of a tungsten but does not remove it. Which of the following is produced? heat characteristic and bremsstrahlung interactions. (between the filament electron and the tungsten atom.) When filament electrons enter the anode target, they mostly interact with outer shell electrons of tungsten atoms. When a filament electron knocks out a K shell electron from the tungsten atom, it leads to a characteristic x-ray photon. The energy of the characteristic x-ray photon depends on the binding energy of the inner-shell electron. the energy level of the filament electron. the shell of the electron that is dropping into the vacancy. A filament electron removes a K shell electron and an M shell electron fills the vacancy. The K shell binding energy is 69.5 keV and the M shell binding energy is 2.8 keV. What is the energy of the K- characteristic photon produced? 66.7 keV (The energy of the photon produced is determined by subtracting the binding energy of the outer shell electron from the binding energy of the inner shell electron (69.5 - 2.8 = 66.7).) Bremsstrahlung means braking radiation. The energy of the brems photon depends on the original energy of the filament electron. the strength of the attraction between the electron and the nucleus. the energy of the filament electron as it leaves the tungsten atom. The majority of the x-ray photons produced are brems photons. Which of the following is the primary factor controlling quantity? mAs As the distance increases, the beam quantity reaching a specific area decreases Classical interactions are also known as Thomson and coherent scattering. Coherent scattering involves an x-ray photon with low energy. With Compton scattering, the incident photon loses up to one third of its energy Secondary photons produced during a Photoelectric interaction contribute to patient dose When it does interact with the image receptor, the Compton scatter photon contributes no useful information because it has changed direction The fog seen on the radiographic image is the result of compton interactions The primary source of radiation exposure to the radiographer who is in the room during an exposure is from scatter from the patient To minimize occupational exposure, the technologist should wear protective apparel (lead aprons, gloves, etc.) when in the room during imaging. Photoelectric interactions Visibility factors of a quality radiograph include: brightness and contrast Which of the following results in a poor- quality digital image because of improper processing due to extreme over exposure to the image receptor. saturation What feature provides a numeric value indicating the level of radiation exposure to the digital image receptor? exposure indicator Anatomic tissues that attenuate the x-ray beam equally are said to have: low subject contrast Unwanted scatter exposure to the image receptor will likely increase: fog What is defined as "The range of exposure intensities an image receptor can accurately detect"? dynamic range For a given field of view (FOV), a _________ matrix size will result in _________pixels. large, more In digital imaging, which of the following determines the range of grayscale available for display? pixel bit depth During digital image display, the contrast can be lowered (decreased) by increasing _____________. window width The ability of the imaging system to distinguish between small objects that attenuate the x-ray beam similarly defines: contrast resolution Increasing the displayed field of view (FOV) for a fixed matrix size will result in: increased pixel size The visibility of anatomic structures is increased with: -increased contrast-to-noise ratio (CNR) -increased signal-to-noise ratio (SNR) An imaging system with a higher detective quantum efficiency (DQE): is more efficient in converting x-ray exposure to a quality image. Double exposing an image receptor will likely result in: image artifact The device that receives the radiation after it exits the patient is the: image receptor Which of the following is an example of an image receptor? Film-screen and digital In producing a radiographic image, which of the following occurs first? Quality and quantity of x-ray beam exit the x- ray tube In producing a radiographic image, which of the following occurs last? Radiation interacts with image receptor The latent image that is formed on the image receptor is the: invisible image. Complete absorption of the diagnostic range x-ray photon is the interaction known as photoelectric interaction. Scatter radiation decreases the visibility of anatomic structures Attenuation depends on: part thickness, tissue density, atomic number, beam energy what type of interaction happens with transmission: no interaction takes place Photoelectric absorption: the photons that are absorbed by the patient's body -interacts with inner-shell electron - photon in, electron out -characteristic cascade produces secondary photons -results in ionization -secondary photons produced contribute to patient dose -ejects photoelectron -predominate at lower kvp Coherent (aka thompson/classical) scattering: the incident x-ray photon interacts with an orbital electron of a tissue atom and changes direction. -x-ray photons with low energy -photon in, photon out -no ionization -decreases contrast -add slightly to patient dose Compton interactions (scattering): Compton interactions are scattering events that ionize the atom. They may contribute negatively to the radiographic image as fog and add to patient and occupational radiation dose. -photon in; photon and electron out. -interacts with outer-shell electron -incident photon loses up to one-third of it's energy and deflected in new direction. -if a middle-shell electron is involved a characteristic cascade results -creates characteristic photon or secondary photons -ejected electron is called a compton electron or secondary electron -occurs at high energy Attenuation: a reduction in x-ray beam intensity as a result of absorption and scatter in matter.