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RAD 1333 Final Exam Questions and
Correct Solutions. Latest 2025. Graded A
_______ is the universal standard exposure indicator. - ANS DI __________ is a method of describing the strength of the radiation exposure compared with the amount of noise apparent in the digital image.
- ANS SNR ___________ is the unit used to measure tube current. Tube current is the number of electrons flowing per unit of time between cathode and anode. - ANSmA ____________ are devices used to measure part thickness. - ANSCalipers ____________ is typically not a factor that is manipulated to vary the amount of exposure reaching the IR because it can also affect the contrast.
- ANSkVp _____________ interactions are produced when a projectile electron ejects a K-shell electron of the tungsten target atom from its orbit. When the K- shell electron is ejected, an outer-shell electron drops into the open position and creates an energy difference which is emitted as an x-ray photon. - ANSCharacteristics
_____________ is the element constituting approximately 90% of the anode target. It is used because of its atomic number (74) which is efficient in x-ray production and has a high melting point. - ANSTungsten _____________ is typically used to measure a patients exposure and is expressed as Gy or mGy (in tissue). - ANSAbsorbed Dose ______________ interactions occur when a projectile electron passes close to the nucleus of the tungsten atom of the target causing the electron to suddenly "slow down", lose energy, and change directions. - ANSBremsstahlung ______________ is defined in your textbook as any unwanted image on a radiograph. - ANSArtifact _______________ is the measure of occupational radiation exposure and is measured in units of Sv or mSv. - ANSDose Equivalent ________________ provides a numerical value indicating the level of exposure to the IR and is vendor specific? - ANSEI _________________ is defined as visible brightness fluctuations (speckled appearance) on a digital image. - ANSquantum noise ___________________ is defined as the height of the lead strips compared to the distance between them? - ANSgrid ratio
A _____________________ grid has lead lines that are angled, or canted, to approximately match the angle of divergence of the primary beam? - ANSfocused A __________, or __________, is a small discrete bundle of energy. - ANSPhoton, Quantum A Deviation Index of 0 (zero) would indicate ____________. - ANSthere is no difference between the desired EI and the actual EI. A digital image is recorded as a ___________ , which is defined as a combination of rows and columns of "picture elements". - ANSMatrix A good quality KUB image was obtained in the radiology department using 85 kVp @ 20 mAs, a 40" SID, and a 12:1 ratio grid. The ER physician requests a KUB on a similar-sized patient in the ER with the mobile x-ray unit which requires the SID to be increased to 46" and the use of a 5:1 ratio grid. The adjustment in the exposure technique required to provide a similar quality image is _________ mAs. - ANS A linear grid with the grid lines (strips) running perpendicular to their long axis is considered a __________________ grid. - ANSshort dimension A pixel that has a bit depth of 4 can display how many shades of gray? - ANS
A purpose of beam-restricting devices is to ______________ by changing the size and shape of the primary beam. - ANSdecrease scatter production A quality image is produced using 75 kVp and 40 mAs at a 72" SID. What calculated change in the exposure technique is necessary to maintain radiation exposure to the IR when the SID is decreased to a 40" SID? (round final answer to the nearest whole #) - ANS12 mAs A quality radiograph is obtained using 5 mAs at 70 kVp without using a grid. In order to maintain the exposure to the IR, what new mAs is needed when adding a 12:1 ratio grid? - ANS25 mAs A radiographic image that displays many shades of gray with little differences between them is said to have ____________ contrast. - ANSLong-scale According to the Gurney-Mott Theory, ______________________ are the sites of latent image formation for radiographic film? - ANSsensitivity specks Accuracy (sharpness) of the structural lines refers to which of the following image quality attribute? - ANSSpatial resolution AEC controls the exposure time and therefore the quantity of radiation reaching the IR. - ANSTrue
Because the mAs is the product of milliamperage (mA) and exposure time (s), increasing either milliamperage or time will have the same effect on the radiation exposure. - ANSTrue Cesium iodide and gadolinium oxysulfide are 2 types of ________________ used in indirect conversion FPDs. - ANSscintillators During attenuation, incoming x-ray photons may lose energy and change directions leading to scatter. This type of photon interaction is known as _____________. - ANSCompton Effect During CR digitizing, increasing sampling frequency and decreasing sampling pitch will give you a ___________________ digital representation of the acquired analog image. - ANSmore accurate During digital image processing, _______________________ provide the means to alter the brightness and grayscale of the image using computer algorithms. - ANSLUT During processing or digitizing of the CR latent image, the PMT collects, amplifies, and converts the visible light to an electrical signal proportional to the range of energies stored in the IP. This stage of digitizing is called _____________________. - ANSSampling During x-ray production, most of the energy produced at the anode is _________. - ANSHeat
Elongation and foreshortening are types of ____________________________. - ANSShape Distortion Excessive radiation exposure to the IR would result in a digital image displayed with ___________________. - ANSacceptable brightness Fixed kVp/Variable mAs technique charts identify optimal kVp values and alter the mAs by a factor of _________ for every _________ cm change in part thickness. - ANS2, 4- Grids are typically only used when the anatomic part is _____ cm or greater in thickness. - ANS How many detectors are typically found in an AEC system? - ANSThree How would an area with increased density on a film-screen image be described when viewed on a digital display monitor? - ANSDecreased brightness If imaginary lines were drawn from each of the lead lines (strips) in a linearly focused grid, these lines would meet to form an imaginary point called the __________________. - ANSconvergent point If the FOV is increased for a fixed matrix, The pixel size will ________________? - ANSIncrease
In terms of digital image quality, what effect does an increase in kVp have on the image contrast? - ANSdecreases image contrast (long-scale) In terms of digital image quality, what effect does an increase in mAs have on the image brightness? - ANSno effect on image brightness In the diagnostic energy range (30 - 150 kVp), most interactions with the tungsten target are ______________ interactions. - ANSBremsstrahlung Increasing or decreasing the kVp by ______ for every ______ cm in part thickness change describes a Variable kVp/Fixed mAs technique chart. - ANS2, 1 Increasing the kVp increases the penetrating power of the x-ray beam which results in ___________ absorption and ___________ transmission in the anatomic tissue. - ANSdecreased, increased Increasing the number of pixels per unit area (pixel density) will _____________ the spatial resolution. - ANSIncrease Increasing the thickness of the phosphor layer and increasing the size of the phosphor crystals will _________________ the speed of the intensifying screen. - ANSIncrease Instilling a negative contrast agent into the GI tract produces what effect on that area of the digital image? - ANSDecreased brightness
It is the radiographer's responsibility to minimize the radiation dose to the patient, to themselves, and to others according to the _____________ Principle. - ANSALARA mAs has _______ on the quality of the x-rays produced. - ANSNo Effect Minimum response time refers to _________________. - ANSthe shortest exposure time possible when an AEC device is used Most of the electron kinetic energy in the tube current is converted to heat whereas less than ____ % is converted to x-rays. - ANS1% Once an anatomically programmed technique has been selected, there is no reason the radiographer should adjust the settings. - ANSFalse One advantage of the mAs readout display of an AEC system is to provides the radiographer a basis for making exposure adjustments. - ANSTrue Plaster casts generally do not require an increase in exposure factors from the values used for the same anatomic part without a cast. - ANSFalse Radio waves, gamma rays, and x-rays are all part of what spectrum? - ANSElectromagnetic
The __________ is a coiled tungsten wire and is the source of electrons during x-ray production. - ANSFilament The ___________ is the electron cloud that is formed around the filament before x-ray production. - ANSSpace Charge The ___________ is the negatively charged electrode of the x-ray tube. - ANSCathode The ___________ provides a numeric value indicating the level of radiation exposure to the digital IR. These values are vendor specific. - ANSEI The ___________ that is set by the radiographer and applied across the x- ray tube at the time of exposure determines the speed at which the electrons in the tube current move. - ANSKVP The ____________ determines the number of shades of gray that can be displayed on a computer monitor. - ANSPixel Bit Depth The ____________ is the distance between the midpoint of one pixel to the midpoint of an adjacent pixel. - ANSPixel Pitch The ____________ of the beam indicates its penetrating power. - ANSQuality The ____________ of the x-ray beam indicates the number of x-ray photons in the primary beam. - ANSQuantity
The ______________ is an alternative for using a grid to control the scatter radiation reaching the IR. It utilizes an increased OID to allow scatter to "miss" the IR. - ANSAir-gap technique The ______________ of a digital system refers to the ability of a detector to accurately capture the range of photon intensities that exit the patient. - ANSdynamic range The ________________ region of a sensitometric curve is where the diagnostic or most useful range of densities are produced. - ANSStraight- line The _________________ heats the tungsten filament which causes thermionic emission. - ANSFilament Current The _________________ indicates how much size distortion or magnification is demonstrated on a radiographic image? - ANSmagnification factor (MF) The __________________ keeps the cloud of electrons emitted from the filament from spreading apart and its purpose is to focus the stream of electrons. - ANSFocusing cup The __________________ refers to the flow of electrons from cathode to anode. - ANSTube Current
The electrons in the tube current ALWAYS travel in only one direction, from __________ to __________. - ANSCathode to Anode The emulsion layer of radiographic film consists of _________________ crystals suspended in gelatin. - ANSsilver halide The grid __________________ refers to the orientation of the lead lines relative to one another. - ANSgrid focus The Grid Conversion Factor (GCF) for no grid is zero. - ANSFalse The high brightness areas on a radiographic image represents areas of _____________. - ANSAbsorbed Radiation The interspace material that seperates the lead strips in a grid is typically made of which of the following materials? - ANSaluminum The main purpose of a technique chart is to__________________. - ANSensure consistent image quality throughout the entire radiology department. The measure of light intensity emitted from the surface of a display monitor is called monitor _________________ and is measured in candela per square meters. (cd/m - ANSLuminance
The monitors used by radiologists for diagnostic interpretation are referred to as _____________________ monitors. - ANSprimary The phenomenon known as the anode heel effect describes how the x-ray beam has greater intensity on the ___________________. - ANSCathode Side of the tube The phosphor layer of the CR imaging plate is composed of ______________ crystals doped with europium, referred to as the PSP. - ANSbarium fluorohalide The pixel size is __________ related to the FOV and ____________ related to the matrix size. *Hint: think of the formula that represents these relationships! - ANSdirectly, inversely The process whereby a radiographic image is created by variations in absorption and transmission of the exiting x-ray beam is known as ______________. - ANSDifferential Absorption The projected shape of the unrestricted primary beam is _____________. - ANScircular The PSP layer of the CR imaging plate traps e- proportional to the tissue's differential x-ray absorption to form the ________________. - ANSlatent image
The TFT array of a flat-panel detector is divided into square __________________ or DEL. - ANSdetector elements The wavelength and frequency of x-ray photons are ____________________. - ANSInversely Proportional The x-ray interaction responsible for total absorption of the incoming x-ray photon is _________________. - ANSPhotoelectric Effect To maintain the same mAs, if you increases the mA you must proportionally __________ the exposure time. - ANSdecrease Too few x-ray photons reaching the IR to form the image, increases the visibility of ____________________ on the radiographic image. - ANSQuantum Noise Unexposed silver from film processing does not have to be collected unless financial rewards are an incentive. - ANSFalse Varies the range of shades of gray (contrast) visible in the image - ANSWindow Width Visibility of the recorded detail refers to which of the following image quality attribute? - ANSBrightness Wavelength is represented by the Greek letter ________. - ANSLambda
What exposure factor change is recommended to maintain radiation exposure to the IR when the anatomic part thickness is increased by 5 cm (2")? - ANSDoubling the mAs What is the classification of the artifact displayed on this image? - ANSMinus-density artifact What is the grid ratio when the lead strips are 2.0 mm high and separated by 0.25 mm? - ANS8: What is the mAs if you select an mA of 400 and an exposure time of 0. seconds? - ANS100 mAs What predominate error is represented on this image? - ANSmotion unsharpness What process is employed to maintain consistent digital image brightness for overexposure and underexposure? - ANSAutomatic rescaling What type of image receptor (IR) uses a photostimulable phosphor (PSP) layer to acquire the latent image. - ANSCR What type of monitor passes light through liquid crystals to display a digital image? - ANSLCD When a radiographer uses an SID that is outside the focal range of a grid, what type of grid error occurs? - ANSOff-focus grid error
