with Accurate Answers
______ the pitch value permits a greater field of view (FOV) to be imaging in a
shorter time correct answer increasing
A method used to measure and reproduce patient table motion during exposure.
What is the term that is used to define this extension or contraction of the helix
correct answer Pitch
A pencil thin beam of radiation that strikes a single detector correct answer Ray
A set of rays striking a detector array( a group of detectors); this is also called a
view correct answer Projection
Attenuation data received by CT detectors is +- _, therefore Hounsfield units are
accurate +- _. correct answer 0.2, 2
Both of these generations used a single-projection, fan shaped beam and had 2-
10 second scan time correct answer Third and Fourth
Consist of brushes fit into grooves to permit the current and voltage to the X-ray
tube to be supplied while the tube is in continuous rotation around the gantry.
correct answer Slip rings
CT magnification is achieved by choosing a ____ display field of view correct
answer smaller
, CT provides more ______ information than any other ionizing radiation imaging
modality. correct answer Diagnostic
CT scanning is usually performed ______ sections, digital processing of
information can produce _____ and _____ sections correct answer
Transverse,sagittal, coronal
Designed to control: data acquisition, processing, display, and storage. correct
answer computers
Detectors used in helical and MSCT, Similar to DR detectors but larger, Large
acceptance angles that allow for the entire array to be used simultaneously.
correct answer Solid State
Detectors with gas filled ionization chambers with the same principles as AEC,
Electrodes made of tungsten with alternately charged voltages, Energy is detected
between the electrodes and converted to digital signal. correct answer Xenon
Ionization Chambers
Determined by how well the detector converts the absorbed photon information
into a digital signal for the computer. correct answer conversion efficiency
Disadvantage of second generation scanners correct answer Loss of collimation
caused increased scatter
Disadvantage of third generation scanners correct answer Prone to ring artifacts