MOSBY'S CT LATEST 2026 TEST PAPER QUESTIONS AND
SOLUTIONS RATED A+
✔✔retrospecting reconstruction - ✔✔reconstruction performed after the initial
prospective reconstruction.
✔✔ring artifact - ✔✔an incorrect ring of density on the reconstructed CT image resulting
from detector malfunction.
✔✔saline flush - ✔✔injection of a volume of normal saline solution immediately
following the bolus injection of a contrast agent; flushes any remaining contrast through
the automated injector tubing, improving the efficiency of contrast utilization.
✔✔scan delay - ✔✔the time between the initiation of contrast administration and CT
data acquisition.
✔✔scan field of view (SFOV) - ✔✔a parameter that controls the diameter of the circular
data acquisition field within the CT gantry as determined by the number of activated
detectors along the x-y axes. may also be referred to as the calibration field.
✔✔scinitllation - ✔✔the production of light energy by a CT detector material in response
to absorbed x-ray energy.
✔✔scout image - ✔✔digital survey radiograph acquired by the CT system for the
purpose of prescribing the cross-sectional acquisition. similar to a conventional
radiograph, it is produced by translating the patient through the gantry without tube and
detector rotation.
✔✔section interval - ✔✔the distance between the center of one CT section and the
center of the next adjacent section.
✔✔section width - ✔✔the dimension of a recontructed CT slice along the longitudinal
direction of acquisition (z-axis). commonly referred to as slice thickness.
✔✔signal - ✔✔electronic current emitted by the CT detector in responce to the
absorption and measurement of transmitted radiation.
✔✔signal-to-noise ratio (SNR) - ✔✔quantification of the amount of noise in a displayed
CT image. calculated as the standard deviation in the ROI measurement of a water
phantom image.
✔✔single-slice CT (SSCT) - ✔✔a CT system with a single row of detectors capable of
acquiring only one image section for each gantry rotation.
, ✔✔slice sensitivity profile (SSP) - ✔✔graph demonstrating the broadening of the section
width that is inherent to volumetric (helical) CT acquisition.
✔✔slip-ring - ✔✔the rotating assembly used to enable the passage of electrical signal
during continuous rotation of the helical CT system.
✔✔spatial frequency - ✔✔the waveform of signal that represents the varied objects
imaged by a CT system.
✔✔spatial resolution - ✔✔the ability of a CT imaging system to display fine details
separately. given in units of line pairs per centimeter (lp/cm)
✔✔step artifact - ✔✔the unwanted appearance of individual sections on a mulitplanar or
3D reformation image resulting in a loss of sharpness and detail.
✔✔stranding - ✔✔hazy increase in density of the fat surrounding an organ on CT
exams that usually indicates an inflammatory process.
✔✔surface rendering - ✔✔construction of a three-dimensional model of a specific tissue
type by limiting the displayed volumetric data on the basis of an attenuation threshold.
may also be reffered to as shaded surface display.
✔✔teleradiology - ✔✔the transmission of image data across networks from the imaging
facility to an offsite location for review and interpretation.
✔✔temporal resolution - ✔✔the ability of a CT system to freeze motion and provide an
image free of blurring.
✔✔total collimation - ✔✔the combined thickness of all of the sections that are
simultaneously acquired with each gantry rotation during MSCT acquisition.
✔✔triple rule-out - ✔✔comprehensive MSCT exam of the chest for cardiac and non-
cardiac pain. the single acquistion evaluates for coronary artery disease, aortic
aneurysm, and pulmonary embolism.
✔✔tube arcing - ✔✔short circuiting within the x-ray tube during data acquisition that
results in severe streak artifacts in the CT image.
✔✔uniform matrix array - ✔✔the type of MSCT detector array that utilized multiple
detectors in the longitudinal direction, each of the same length.
✔✔uniformity - ✔✔maintenance of relatively consistent CT values across the entire
image of an object of equal density.
SOLUTIONS RATED A+
✔✔retrospecting reconstruction - ✔✔reconstruction performed after the initial
prospective reconstruction.
✔✔ring artifact - ✔✔an incorrect ring of density on the reconstructed CT image resulting
from detector malfunction.
✔✔saline flush - ✔✔injection of a volume of normal saline solution immediately
following the bolus injection of a contrast agent; flushes any remaining contrast through
the automated injector tubing, improving the efficiency of contrast utilization.
✔✔scan delay - ✔✔the time between the initiation of contrast administration and CT
data acquisition.
✔✔scan field of view (SFOV) - ✔✔a parameter that controls the diameter of the circular
data acquisition field within the CT gantry as determined by the number of activated
detectors along the x-y axes. may also be referred to as the calibration field.
✔✔scinitllation - ✔✔the production of light energy by a CT detector material in response
to absorbed x-ray energy.
✔✔scout image - ✔✔digital survey radiograph acquired by the CT system for the
purpose of prescribing the cross-sectional acquisition. similar to a conventional
radiograph, it is produced by translating the patient through the gantry without tube and
detector rotation.
✔✔section interval - ✔✔the distance between the center of one CT section and the
center of the next adjacent section.
✔✔section width - ✔✔the dimension of a recontructed CT slice along the longitudinal
direction of acquisition (z-axis). commonly referred to as slice thickness.
✔✔signal - ✔✔electronic current emitted by the CT detector in responce to the
absorption and measurement of transmitted radiation.
✔✔signal-to-noise ratio (SNR) - ✔✔quantification of the amount of noise in a displayed
CT image. calculated as the standard deviation in the ROI measurement of a water
phantom image.
✔✔single-slice CT (SSCT) - ✔✔a CT system with a single row of detectors capable of
acquiring only one image section for each gantry rotation.
, ✔✔slice sensitivity profile (SSP) - ✔✔graph demonstrating the broadening of the section
width that is inherent to volumetric (helical) CT acquisition.
✔✔slip-ring - ✔✔the rotating assembly used to enable the passage of electrical signal
during continuous rotation of the helical CT system.
✔✔spatial frequency - ✔✔the waveform of signal that represents the varied objects
imaged by a CT system.
✔✔spatial resolution - ✔✔the ability of a CT imaging system to display fine details
separately. given in units of line pairs per centimeter (lp/cm)
✔✔step artifact - ✔✔the unwanted appearance of individual sections on a mulitplanar or
3D reformation image resulting in a loss of sharpness and detail.
✔✔stranding - ✔✔hazy increase in density of the fat surrounding an organ on CT
exams that usually indicates an inflammatory process.
✔✔surface rendering - ✔✔construction of a three-dimensional model of a specific tissue
type by limiting the displayed volumetric data on the basis of an attenuation threshold.
may also be reffered to as shaded surface display.
✔✔teleradiology - ✔✔the transmission of image data across networks from the imaging
facility to an offsite location for review and interpretation.
✔✔temporal resolution - ✔✔the ability of a CT system to freeze motion and provide an
image free of blurring.
✔✔total collimation - ✔✔the combined thickness of all of the sections that are
simultaneously acquired with each gantry rotation during MSCT acquisition.
✔✔triple rule-out - ✔✔comprehensive MSCT exam of the chest for cardiac and non-
cardiac pain. the single acquistion evaluates for coronary artery disease, aortic
aneurysm, and pulmonary embolism.
✔✔tube arcing - ✔✔short circuiting within the x-ray tube during data acquisition that
results in severe streak artifacts in the CT image.
✔✔uniform matrix array - ✔✔the type of MSCT detector array that utilized multiple
detectors in the longitudinal direction, each of the same length.
✔✔uniformity - ✔✔maintenance of relatively consistent CT values across the entire
image of an object of equal density.
