IMAGE ACQUISITION AND EVALUATION Flashcards
Underexposure of a radiograph can be caused by all the following except insufficient A. milliamperage (mA) B. exposure time C. Kilovoltage D. SID
SID
Which of the following can affect the amount of developer replenisher delivered per film in an automatic processor? A. Developer temperature B. Amount of film exposure C. Film size D. Processor capacity
Film size
Due to the high sensitivity of digital detectors to low intensity radiation (background, scatter and/or off-focus radiation), there is likely to be scatter and off-focus radiation contributing to the image outside the collimation margins. Since many radiologists find this distracting, the most appropriate radiographer action would be to:
A. Use film-screen imaging only
B. Apply a black border to the image before it is printed or sent to PACS
C. Expose the anatomical parts as is; there is nothing that can be done to improve the presentation of the image(s) due to the inherent sensitivity of the system
D. Reduce exposure factors by one-half to ensure minimal scatter and off-focus radiation
Apply a black border to the image before it is printed or sent to PACS
While indirect digital detectors use a scintillator (phosphor) to convert X-ray energy, direct detectors use a: A. Photoconductor B. Scintillator C. Charged coupled device D. Histogram detector screen
Photoconductor
All the following have an impact on radiographic contrast except A. photon energy B. grid ratio C. OID D. focal-spot size
focal-spot size
Geometric blur can be evaluated using all the following devices except A. star pattern B. slit camera C. penetrometer D. pinhole camera
penetrometer
Which of the following conditions will require an increase in x-ray photon energy/penetration? A. Fibrosarcoma B. Osteomalacia C. Paralytic ileus D. Ascites
Ascites
The absorption of useful radiation by a grid is called A. grid selectivity. B. grid cleanup. C. grid cutoff. D. latitude.
grid cutoff.
Silver reclamation may be accomplished in which of the following ways?
Metallic replacement cartridge Electrolytic plating unit Removal from used film
A. 1 only
B.2 only
C. 1 and 2 only
D. 1, 2, and 3
D. 1, 2, and 3
Which of the following statements regarding dual x-ray absorptiometry is (are) true?
- Radiation dose is low.
- Only low-energy photons are used.
- Photon attenuation by bone is calculated.
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2, and 3
C. 1 and 3 only
A film emulsion having wide latitude is likely to exhibit A. high density B. low density C. high contrast D. low contrast
low contrast
Which of the following is likely to contribute to the radiographic contrast present on the finished radiograph?
- Atomic number of tissues radiographed
- Any pathologic processes
- Degree of muscle development
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2, and 3
D. 1, 2, and 3
Better resolution is obtained with A. high SNR. B. low SNR. C. windowing. D. smaller matrix.
A. high SNR.
A grid is usually employed
- when radiographing a large or dense body part.
- when using high kilovoltage.
- when less patient dose is required.
C. 1 and 2 only
An exposure was made at a 36-in. SID using 12 mAs and 75 kVp with a 400-speed imaging system and an 8:1 grid. A second radiograph is requested with improved recorded detail. Which of the following groups of technical factors will best accomplish this task?
A. 15 mAs, 12:1 grid, 75 kVp, 400-speed system, 36-in. SID
B. 15 mAs, 12:1 grid, 75 kVp, 400-speed system, 40-in. SID
C. 30 mAs, 12:1 grid, 75 kVp, 200-speed system, 40-in. SID
D. 12 mAs, 8:1 grid, 86 kVp, 200-speed system, 36-in. SID
C. 30 mAs, 12:1 grid, 75 kVp, 200-speed system, 40-in. SID