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imaging q&a worksht
imaging q@a worksheet
| Question | Answer |
|---|---|
| computed radiography is superior to film screen radiography in | contrast resolution |
| converting an analog image to a digital image is accomplished thru the use of | film digitizer |
| which matrix will have the largest pixel size | 256 X 256 |
| which matrix will have the smallest pixels | 2048 X 2048 |
| which type of projection radiography image receptor has the highest spatial resolution | film screen radiography |
| a CR artifact caused by insufficient mAs is | quantum mottle |
| a photostimulable imaging plate includes a ___ layer | phosphor, conductor, protective |
| a radiograph that demonstrates considerable differences between densities is called | short scale, high contrast, increased contrast |
| a radiograph that demonstrates minimal differences between densities is called | long scale, low contrast, decreased contrast |
| a radiograph with few shades of gray exhibits | high contrast |
| a rectifier | converts AC to DC |
| a stator consists of | electromagnets |
| a three-phase rectified current produces a voltage ripple of ___ pulses per Hz | 6 |
| a transformer with more secondary windings than primary windings | has a greater secondary voltage |
| adjustments in kVp should be used to control radiographic | contrast |
| american generators operate at | 60 Hz |
| an eight-bit word is called a | byte |
| an image bit depth of 2^8 or 8 bit will have how many shades of gray associated with each picture | 256 |
| an increase in kVp by 15% will cause an approximate ___ in the exposure | doubling |
| as kVp ___, a ___ range of photon energies is produced | increase, wider |
| as the mAs doubles, the # of electrons flowing from cathode to anode increases | twofold |
| as the slope of the D log E curve ___, contrast ___ | increases, increases |
| at what point in the x-ray tube circuit is the rectification circuit located | between the step-up transformer and the x-ray tube |
| backup time | cannot exceed the tube limit, should set a 150% of the expected manual mAs |
| bremstrahlung interactions may occur only when the incident electron interacts with | the force field of the nucleus |
| characteristic interactions mat occur only when the incident electron interacts with | an inner shell electron |
| computers operate from a ___ language | binary |
| cracking of the anode commonly occurs | when the unit is not warmed up properly |
| detectors currently used in computed radiography include all of the following execpt | capacitor plates |
| digital radiography cassettes are also known as | filmless cassettes |
| digital radiography replaces | traditional film |
| driving the thermionic cloud from the cathode to the anode requires | a large potential difference |
| during a characteristic interaction, the dropping of a higher-energy electron into a lower-energy hole results in the emission of | a photon of energy |
| during a characteristic interaction, the energy of the incident electron must be ___ the electron it knocks from its orbit | greater than that of |
| during fluoroscopic image intensification, the primary x-ray beam exits the pt & strikes the ___ of the image intensifier | input screen |
| during photoelectric absorption, the ejected electron is called | photoelectron |
| during the process of attenuation, the x-ray photon may interact with | the nucleus, the entire atom, an orbital electron |
| during the process of attenuation, x-ray photons in the beam | reduce in #, lose energy, interact |
| during the two-part conversion system, a ___ converts x-ray photons to light | scintillator |
| during the two-part conversion system, a ___ converts light into an electronic digital signal | photodetector |
| each binary number is called a | bit |
| electric potential is measured in | volts |
| electronic lenses are used to accelerate & focus | electrons |
| fluoroscopy is a ___ radiographic examination | dynamic, static, diagnostic |
| fluoroscopy is commonly used for observation of | the heart, surgical procedure, the GI tract |
| high contrast is directly related to | the # of photoelectric interactions |
| high-speed systems tend to have ___ resolution | low |
| how many alterations in the direction of the current flow occur per second in a 60Hz AC current | 120 |
| how many times does an AC current change direction in a single minute | 7200 |
| if a photon interacts with matter and scatters, the photon | exists with less energy |
| if the mAs of a radiograph is increased from 10 to 20, the resulting radiograph will exhibit | increased radiographic density |
| image receptor contrast is expressed as the ___ of the D log E curve | slope |
| increasing the energy of an incident electron will result in the production of an x-ray photon with | greater energy |
| increasing the kVp on an x-ray control panel will cause ___ across the x-ray tube | an increase in the speed of electrons |
| kilovoltage is the primary controller of | contrast |
| melting of the anode commonly occurs | when the stator fails & the rotor ceases to turn |
| milliamperage-second directly affects each of the following except | quality |
| narrow latitude systems exhibit ___ contrast | high |
| nearly all x-ray equipment operates from an incoming line of | 220-240 V |
| pitting of the anode commonly occurs | with extended use |
| production of a grainy, reticulated image that cannot be corrected in digital post-processing is the result of | failure to use a high enough mAs setting |
| resolution is controlled by ___ size | pixel |
| silicon & selenium are also known as | flat panel detectors |
| the active layer of the CR imaging plate is made of | photostimulable fluorohalides |
| the area of the focal spot that is projected out of the tube toward the object being radiographed is the | effective focal spot |
| the controlling factor of contrast is | kVp |
| the CR imaging plate is scanned by a | helium- neon laser beam |
| the density maintenance formula is a | direct square law |
| the detail of a radiographic image is visible because of | sufficient contrast & sufficient density |
| the difference between two adjacent densities is | contrast |
| the electrical device used to adjust the mA selection is the | variable resistor |
| the energy of a bremstrahlung photon is | the difference between the entering & exiting kinetic energy of the electron |
| the exposure switch is found between the | autotransformer and the timer circuit |
| the exposure switch on an x-ray machine is intended to | initiate the exposure |
| the factors that affect x-ray emission under the direct control of the radiographer are called ___ factors | prime |
| the factors that directly affect x-ray quality are | kVp & filtration |
| the factors that directly affect x-ray quantity are | mAs, distance, filtration |
| the function of the cathode is to produce | a thermionic cloud |
| the histogram generated from the image data allows the digital system to find the | min, max signal within the anatomical area of interest & shades of gray |
| the incoming line current is supplied | in the form of three-phase power cycle |
| the input screen absorbs ___ and emits ___ | x-ray photons, light photons |
| the k-shell can hold a max # of ___ electrons | 2 |
| the kVp control is found between the | incoming line and the exposure switch |
| the latent image is created by energy transfer during | photoelectric interactions |
| the mA control is found between the | incoming line and the step-down transformer |
| the mA is a unit of | current |
| the most common phosphor used for computed radiography imaging plates is | barium fluorohalide bromides and iodides with europium activators |
| the common solution for quantum mottle is | increase the fluoro tube mA |
| the output screen absorbs ___ and emits ___ | electrons, light photons |
| the photocathode absorbs ___ and emits ___ | light photons, electrons |
| the physical area of the focal track affected by the electron beam is the | actual focal spot |
| the primary control of x-ray quantity is governed by | mAs |
| the primary ___ occurs from the acceleration & focusing of the electron beam | brightness gain |
| the prime factors include each of the following except | filtration |
| the process of electrons being emitted from heated metallic surfaces is called | thermionic emission |
| the process whereby there is continual assessment of the entire organizational process for quality improvement is called | continuous quality improvement (CQI), total quality management (TQM), total quality improvement (TQI) |
| the product of tube current & exposure time is equal to | x-ray quantity |
| the relationship between mAs & exposure is | directly proportional |
| the relationship between the intensity of radiation & distance is the | inverse square law |
| the relationship between the relative speed # & the sensitivity of the film-screen combination is | inversely proportional |
| the response of the imaging plate to ionizing radiation is | linear |
| the standard for communication of medical images is | DICOM |
| the time control is found between the | exposure switch and the step-up transformer |
| the unit of electrical power is | watt |
| window level controls | image density |
| window width controls | image contrast |
| total brightness gain is | a measure of the increase in image intensity, determined by minification gain, determined by flux gain |
| unwanted densities caused predominantly by scattered photons are called | radiation fog |
| what percentage of target interactions results in the production of x-ray photons | 1% |
| when an x-ray passes thru matter, it undergoes a process called | attenuation |
| when the x-ray photon with a slightly greater energy than the binding energy of the inner-shell electron interacts with that inner-shell electron, the following interaction results | photoelectric absorption |
| when the CR imaging plate is scanned, the photons of the latent image release energy in the form of | light |
| when the main power to the computer is turned off, ___ is erased | RAM |
| when x-ray photons interact with matter and change direction, the process is called | scatter |
| where is the stator of the anode induction motor located | outside the glass envelope & outside the rotor |
| which atomic shell possesses the highest binding energy | k |
| which condition is needed to produce an x-ray | a source of electrons, a vacuum, a large potential difference |
| which matrix will have the smallest pixels | 1024 X 1024 |
| which of the following interactions has a significant impact on the x-ray image | photoelectric absorption |
| which of the following interactions with matter results in a radiograph with a long scale of contrast | compton scattering |
| which of the following would affect the production of a thermionic cloud | filament length, filament diameter, filament temperature |
| which type of system uses a two-part process to convert incoming x-ray photons to an electric digital signal | indirect conversion |
| x-ray photon production occurs at the | anode |
| x-ray quality is numerically represented by | HVL |
Created by:
reetherockgoddess