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RADT 465: QC
ARRT registry review covering Equipment Operation and Quality Control
Question | Answer |
---|---|
What type of xray tube is designed to turn on and off rapidly, providing multiple short, precise exposures? | grid-controlled (Lang Q&A, 279) |
What are three components of the GT gantry? | xray tube, multidetector array, high-voltage generator (Lang Q&A, 279) |
A parallel-plate ionization chamber receives a particular charge as xray photons travel through it isknown as what operating principle? | AEC (Lang Q&A, 281) |
Congruence of the xray beam with the light field is tested using what? | radiopaque objects (Lang Q&A, 281) |
What is the relationship between kV and HVL? | As kV increases, HVL increases (Lang Q&A, 282) |
As window level increases, what happens to brightness? | increases (Lang Q&A, 282) |
What converts electrical energy to mechanical energy? | motor (Lang Q&A, 282) |
What is a slit camera used to measure? | focal-spot size and spatial resolution |
What are the advantages of collimators over aperture diaphragms and flare cones? | the variety of field sizes available and more efficient beam restriction (Lang Q&A, 283) |
What occurs during Bremsstrahlung radiation production? | an electron approaching a po(Lang Q&A, 283)sitive nuclear charge changes direction and loses energy |
What is the voltage ripple associated with a three-phase, six-pulse rectified generator? | 13 percent (Lang Q&A, 283) |
What process is when a high-speed electron entering the tungsten target is attracted to the positive nucleus of a tungsten atome and then is decelerated | Bremsstrahlung (Lang Q&A, 284) |
What is used in digital fluoroscopy, replacing the image intensifier's television camera tube? | charge-coupled device (Lang Q&A, 284) |
What does the resulting image look like when a three-phase timer can be tested for accuracy using a synchronous spinning top? | solid arc, with the angle (in degrees) representative of the exposure time (Lang Q&A, 284) |
What device is adjusted when the radiographer selects the kilovoltage on the control panel? | autotransformer (Lang Q&A, 284) |
What are star and wye configurations are related to? | three-phase transformers (Lang Q&A, 284) |
What device directs the light emitted from the image intensifier to various viewing and imaging apparatus? | beam splitter (Lang Q&A, 285) |
What systems functions to compensate for changing patient/part thicknesses during fluoroscopic procedures? | automatic brightness control (Lang Q&A, 285) |
What are disadvantages of moving grids over stationary grids? | they can prohibit the use of very short exposure times and they can increase patient radiation dose (Lang Q&A, 286) |
How accurate ,ust the kV settings be when tested annually? | +/- 4 kV (Lang Q&A, 286) |
An incorrect relationship between the primary beam and the center of a focused grid results in what? | grid cut off and insufficient radiographic density (Lang Q&A, 286) |
What kind of beam is the xray tube in CT imaging systems is most likely associated with? | a pulsed xray beam (Lang Q&A, 286) |
The total brihgtness gain of an image intensifier is the product of what? | flux gain and focusing gain (Lang Q&A, 287) |
A spinning-top device can be used to evaluate what? | timer accuracy and rectifier failure (Lang Q&A, 287) |
What is the device used to ensure reproducible radiogrpahs. regardless of tissue-density variations? | automatic exposure control (Lang Q&A, 287) |
What device is used to change alternating current to unidirectional current? | a solid-state diode (Lang Q&A, 287) |
What controls the path of electron flow from the photocathode to the output phosphor (to maintain image clarity in an image-intensifier system? | electrostatic lenses (Lang Q&A, 287) |
What does the image-intensifier tube's input phosphor functions to convert? | xrays to light (Lang Q&A, 287) |
What equipment is mandatory for performance of a myelogram? | tilting xray table (Lang Q&A, 288) |
What characteristics of xray tube targets determine heat capacity? | the rotation of the anode, diameter of the anode and the size of the focal spot (Lang Q&A, 288) |
What describes the amount of electrical charge flowing per second? | Current (Lang Q&A, 289) |
What does moving the image intensifier closer to the patient during fluoroscope do? | decrease SID, decrease patient dose, improves image quality (Lang Q&A, 289) |
What are the advantages of battery-powered mobile x-ray units? | ability to store a large quantity of energy and to store energy for extended periods of time (Lang Q&A, 290) |
What circuit device permits electrons to flow in only one direction? | solid-state diodes (Lang Q&A, 290) |
What principle would an AEC device operate on? | a photomultiplier tube charged by a fluorescent screen and a parallel plate ionization chamber charged by xray photons (Lang Q&A, 290) |
What functions to increase milliamperage? | increase in heat of the filament (Lang Q&A, 290) |
What special application does fractional focus tubes with a .3 mm focal spot or smaller in? | magnification radiography (Lang Q&A, 290) |
What device is used to control voltage by varying resistance? | Rheostat (Lang Q&A, 292) |
What will the anode angle have an effect on? | severity of the heel effect, focal spot size and heat load capacity (Lang Q&A, 292) |
What are light sensitive AEC devices known as? | phototimers (Lang Q&A, 292) |
What devices are components of a typical fluoroscopic video display system? | TV camera and TV monitor (Lang Q&A, 292) |
What is the voltage across the xray tube in three phase equipment? | 87-96% of the maximum value and is at nearly constant potential (Lang Q&A, 293) |
Wha material would be appropriate for the IP front material? | magnesium and bakelite (not tungsten) (Lang Q&A, 293) |
What does the accurate operation of the AEC device depend on? | positioning of the object with respect to the photocell and beam restriction (Lang Q&A, 294) |
What is the image intensifier's input phosphor generally composed of> | cesium iodide (Lang Q&A, 294) |
The total number of xray photons produced at the target is contingent on what? | tube current, target material and square of kilovoltage (Lang Q&A, 294) |