WorksheetsRAD 121 Chap 34-35
Total questions: 10
Worksheet time: 5mins
In a DR image receptor, smaller dels have a:
lower fill-factor
smaller TFTs
higher fill-factor
smaller capacitors
For indirect-conversion DR systems, why is amorphous silicon used rather than amorphous selenium for the semiconductor layers of the detector elements (dels)?
silicon is easier to coat into very thin layers
silicon binds better to the cesium iodide layer above
the molecule must be suited to absorbing light rather than x-rays
silicon is a better electrical conductor
Computed radiography (CR) is a digital imaging technique that acquires image data from:
an electrostatic image receptor scanned by a CCD
a photostimulable phosphor plate scanned by a laser beam
a rare earth intensifying screen scanned by a PM tube
a magnetic tape that has been scanned by a magnetic recorder
The CR cassette must be structured so as to protect the phosphor plate inside it from:
heat
static electricity
primary x-rays
light
During the reading process, the intensity of light emitted by the CR plate phosphor is directly proportional to:
the original kVp used for the radiographic technique
the amount of x-ray energy absorbed in the plate
the voltage applied to the photomultiplier (PM) tube
the amount of quantum mottle present in the image
When a photostimulable phosphor plate is stimulated by a laser beam, the color of light emitted from a barium fluorohalide crystal is:
orange
ultraviolet
blue-violet
yellow-green
The sampling frequency of a CR reader, which determines the number of measurements taken across the phosphor plate, is called the:
aliasing frequency
fast-scan frequency
Nyquist frequency
Larmour frequency
The only prominent disadvantage of the liquid crystal diode (LCD) monitor is related to its:
viewing angle
veiling glare
reflective glare
image sharpness
The liquid crystal diode (LCD) operates on the principle of:
light emission by stimulated fluorescence
light emission by phosphorescence
the polarization of light
light emission by incandescence
A 5-megapixel LCD screen presents much higher ________ than a 3-megapixel LCD:
response rate
viewing angle
resolution
contrast
