Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
171 Final
| Question | Answer |
|---|---|
| Is the distortion of image-intensified fluoroscopic image that appears as unequal magnification: | Pincushion appearance |
| Releasing the pressure applied to the______will terminate the radiation exposure during fluoroscopy: | Deadman switch |
| Is coated with light-emitting crystals to absorb electrons and emit light: | Output phosphor |
| Absorbs light and converts light to electrons: | Photocathode |
| The gain related to the decrease in size from the input to the output phosphor that increases the light intensities is the: | Minification gain |
| In reference to image intensification, the function that adjusts and maintains the overall image brightness and contrast during fluoroscopic procedure is: | ABC |
| Magnification of the fluoroscopic image results in improved: | Spatial resolution |
| Is essentially the sum total of air kerma over the exposed area of the patient’s body surface: | Dose area product |
| Types of ionizing radiation that produce virtually the same biologic effect for equal absorbed doses in body tissue? | X-rays, beta particles, and gamma rays |
| Units are not SI units: | Roentgens, rads and rems |
| Scatter radiation is primarily the result of: | Compton interaction |
| The probability of a Compton interaction occurring is related to: | The energy of the x-ray photon |
| The two major factors that affect the amount of scatter radiation production produced and exiting the patient are: | Volume of tissue irradiated and kVp |
| The volume of tissue irradiated is determined by: | Area of collimation, patient thickness, field size |
| The most effective and often used radiographic beam restriction device is the: | Collimator |
| The field shape produced by a Collimator is: | Rectangular |
| The purpose of automatic collimation is: | Limiting patient exposure |
| A focus grid lead strips are angled to match: | The angle of the x-rays in the primary beam |
| The recommended SID that can be used with focused grid is the: | The focal range |
| To compensate for the reduction of radiation reaching the IR when grid is used___ is typically increased: | mAs |
| Absorption of transmitted photons by a grid caused by misalignment is: | Grid cutoff |
| A grids provides excellent scatter clean-up but requires close to perfect alignment to avoid cutoff: | 16:1 ratio |
| Air-gap technique reduces the amount of scatter radiation reaching the IR because of: | More scatter misses the IR |
| T/F When using automatic collimation, collimating to the anatomy of interest is an unnecessary waste of time; the beam is already collimated: | False |
| T/F grids absorbed almost all the scatter radiation and allow all of the transmitted photons to pass through to the IR: | False |
| T/F adding a grid or increasing grid ratio results in an increase in patient dose: | True |
| Absorbs x-rays and emits light: | Input phosphor |
| Is bonded directly to the input phosphor: | Photocathode |
| Photoemission occurs at the: | Photocathode |
| Is found along the entire length of the image intensifier: | Electrostatic focusing lenses |
| When operated in magnification mode, the electrostatic lenses have ___of a negative charge: | More |
| The disadvantage of using magnification mode during fluoroscopy is: | Patient receives additional dose |
| When the electrons beam is sweeping the anode, if the electron beam and light from the output phosphor are incident on the same place at the same time, ______through the target to the signal plate: | Electron transmitted |
| With digital systems, this is important to monitor to avoid dose creep: | Exposure index number |
| A histogram: is a technique chart, a graph of all data points, extraction of the latent image, values of interest? | A graph of all data points |
| With digital systems, the two detector types are: | CR and DR |
| Are not additive disease: | Bowel obstruction |
| Device that measure part of thickness: | Calipers |
| Back-up time for AEC exposure should be set to: | 150-200% of expected exposure time |
| AEC determines exposure by controlling the? | Length of exposure |
| When using mag mode, voltage to the focusing lenses is: | Increased |
| The increase brightness in fluoroscopy? | Image intensifier |
| When using the air-gap technique, the ___ must also be increased: | SID |
| The number of lead lines per unit length is the: | Grid frequency |
| Which is the most common beam restricting device: | Collimators |
| Are beam restricting devices? | Cylinders, Collimator, aperture diaphragm |
| The SI equivalent for REM is? | Sievert |
| The SI equivalent of RAD is: | Gray |
| T/F the latent image from the PSP plate remains in place for hours after exposure: | True |
| T/F digital systems are more sensitive to scatter radiation: | True |
| Part of the direct capture DR system, the____absorbs x-rays and produces an electronic signal: | Photoconductor |
| T/F histogram analysis is the basis for determining exposure index: | True |
| The Bucky factor(Grid conversion factor) for a grid ratio of 8:1 is? | 4 |
| Part of PSP plate that includes a random distribution of crystals is the: | Turbid phosphor layer |
| The most important layer for creating the image; the layer of film that is sensitive to light or radiation is the: | Emulsion |
| What is the role of the CCD in indirect DR? | Converts light to electrons |
| Component of the CR reader converts light to an electronic signal? | Photodetector |
| What part of the CR reader digitizes the signal? | ADC |
| Describes the extra step, and is therefore a limitation of indirect-capture methods? | X-ray are converted to light and then to electrons |
| T/F grids are used with digital systems in the same way as film/screen? | True |
| Statement is concerning computed radiography(CR) system: | Use Storage phosphor and require the storage phosphor |
| Sequences of events for indirect capture systems in order: | Absorbed, transmitted, converts, signal |
| Correct order for automatic film processing: | Developing, fixing, washing, drying |
| The scintillator for the indirect capture DR system that utilizes a CCD is: | Cesium iodide |
| Part of DR system with indirect capture, the light-sensitive device that is commonly in digital cameras is the: | CCD |
| Intensifying screens are used to: | Reduce patient exposure, convert x-ray photons |
| Once the image is required, what is the role of PACS? | Display and storage |
| T/F with digital systems, a higher kVp can be used than with film/screen: | True |
| Part of the CR reader detects light released from the PSP plate: | Photo detector |
| Fluorescence refers to: | The ability of phosphors to emit visible lights only while exposed to x-rays |
| Digital imaging control focuses on: | Display and viewing |
| T/F the DAP is used for DR digital systems and is a measure of the dose to the patient: | True |
| When the PSP plate is exposed to the laser of the reader, the energy is released and converted to a digital signal, becoming a: | Manifest image |
| What is the primary difference of direct DR over indirect DR? | Lacks the conversion of x-rays to light |
| The DR image capture method that uses an amorphous silicon photodetector and TFT represents of the: | Indirect |
| Delivery of hot air to the surface of the film is the function of: | Drying |
| The type of phosphor found in the PSP plate for computed radiography is: | Barium fluorohalide |
| What part to the flat-panel DR converts x-rays to light? | Scintiliator |
| T/F DR image receptors do not use histograms: | False |
| Europium is the_____of the photostimulable phosphor: | Activator |
| T/F after the digital data leaves the ADC, the process of digital image formation is very different for the three types of DR systems: | False |
| Histogram analysis compares the histogram with pre established histogram specific to: | The anatomic part being imaged |
| DICOM serves what purpose in PACS? | Allow different system to communicate |
| T/F direct DR does not use a scintillator: | True |
| Is the standard format for digital medical Image: | DICOM |
| The part of a PSP plate that gives some rigidity to the plate is the: | Support layer |
Created by:
Faithshay