MOSBY'S CT UPDATED 2026 EXAM SCRIPT QUESTIONS
AND SOLUTIONS RATED A+
✔✔bow-tie filter - ✔✔a type of filter added to the CT x-ray tube to compensate for the
cylindrical shape of most body parts. the filter is thicker at the ends and helps shape the
beam to reduce patient radiation exposure.
✔✔cardiac cycle - ✔✔the series of blood-flow related events that occur from the
beginning of one heartbeat to that of the next.
✔✔cerebral blood flow (CBF) - ✔✔a common measurement during CT perfusion studies
of the brain. CBF is the quantity of blood (mL) that moves through 100 g of brain tissue
each minute. normal range in gray matter is 50 to 60 mL/100 g/min
✔✔cerebral perfusion - ✔✔the level of blood flow throughout brain tissue.
✔✔constant mAs - ✔✔the product of milliamperage (mA) and scan time (seconds)
utilized for a CT acquisition.
✔✔contiguous images - ✔✔CT images acquired with equal section thickness and
reconstruction intervals
✔✔contrast resolution - ✔✔the ability of a CT system to detect an object with a small
difference in linear attenuation coefficient with the surrounding tissue. may also be
referred to as low-contrast detectability or sensitivity.
✔✔contrast-induced nephrotoxicity (CIN) - ✔✔a substantial decline in renal function that
can occur after a patient receives IV contrast material. it is usually signified by a marked
increase in serum creatinine over a baseline measurement obtained prior to contrast
agent administration.
✔✔convolution - ✔✔mathematical filatration used by the CT system to remove blurring
artifact during the back-projection method of image reconstruction
✔✔corticomedullary phase - ✔✔a late arterial phase of renal enhancement beginning
30 to 40 seconds after the initiation of contrast agent administration. optimal
enhancement of the renal cortex and renal veins occurs during this period.
✔✔creatinine - ✔✔a waste product of metabolism found in the bloodstream and
measured as an indicator of renal function. normal range is 0.5 to 1.5 mg/dL.
✔✔CT arthrography - ✔✔CT evaluation of a joint after the intra-articular injection of
iodinated contrast material.
,✔✔CT bronchography - ✔✔specialized MSCT examination of the tracheobronchial tree
consisting of MPR and volume-rendered 3D images reconstructed from thin,
overlapping MDCT axial images through the airways.
✔✔CT colonography - ✔✔specialized CT evaluation of the large intestine used primarily
for colon cancer screening. the large intestine is extended and scanned with thin-
section CT. 2D and 3D models are constructed, including virtual endoscopic fly-through
views.
✔✔CT dose index (CTDI) - ✔✔an approximate measure of the radiation dose received
in a single CT section or slice.
✔✔CT enteroclysis - ✔✔specialized CT evaluation of the small bowel whereby enteral
contrast material is administered directly into the duodenum through a nasogastric
catheter placed under fluoroscopic guidance.
✔✔CT enterography - ✔✔specialized CT evaluation of the small bowel after the oral
administration of low-density (0.1%) barium.
✔✔CT fluoroscopy - ✔✔continuous, real-time CT imagine used predominantly for CT
guided interventional procedures.
✔✔CT myelography - ✔✔Ct evaluation of the spinal cord and nerve roots after the
intrathecal administration of iodonated contrast material.
✔✔CT number - ✔✔relative value assinged to each pixel to quantify the attenuation
occurring in each voxel in comparison with the attenuation of water. Given in Hounsfield
units (HU) may also be referred to as pixel value.
✔✔CT runoff - ✔✔the CT angiographic assessment of the peripheral artierial tree from
the renal arteries through the lower extremeties.
✔✔CT simulation - ✔✔the process of obtaining anatomic information with CT imaging
that is used to calculate the beam arrangement for radiotherapy.
✔✔Ct urogram - ✔✔a comprehensive, multiphasic CT evaluation of the urinary tract.
consists primarily of pre-contrast, post-contrast, and delayed CT acquisitions through
the kidneys, ureters, and bladder. it may also be commonly referred to as a CT-IVP.
✔✔cupping artifact - ✔✔an error appearing in the superior portion of the skull, where
dense bone average with the low-attenuating brain tissue. this partial volume artifact
may result in abnormally dense-appearing brain parenchyma.
, ✔✔data acquisition system (DAS) - ✔✔the electronic components of a CT system
responsible for measuring the transmitted x-radiation absorbed by the detectors.
✔✔data channel - ✔✔pathway of data transmission from the detectors to the
computerized components of the system's data acquisition system. the number of
channels of a CT system determines the maximum number sections that may be
acquired with each gantry rotation.
✔✔data transer rate - ✔✔the speed at which computerized storage drive is able to
transer data
✔✔deconvolution - ✔✔mathematical image processing technique used to generate
blood perfusion maps during CT perfusion studies of the brain.
✔✔detector - ✔✔device responsible for measuring transmitted radiation and converting
it into a proportionate electronic signal to be used for image reconstruction.
✔✔detevtor array - ✔✔the CT image receptor, consisting of a series of detectors
arranged in varying configurations.
✔✔detector collimation - ✔✔the process of determining section width in the MSCT
system as determined by the defined beam width and the number and thickness of
detectors utilized for image reconstruction.
✔✔detector configuration - ✔✔the number, length, and organization of the individual
detector elements in an MSCT system
✔✔detector pitch - ✔✔the ratio of table feed per gantry rotation to the acquired section
width. this definition of pitch is used for helical single-slice CT (SSCT)
✔✔diastole - ✔✔portion of the cardiac cycle when the heart muscle is relaxed. it is the
bottom number provided during the assessment of blood pressure.
✔✔DICOM - ✔✔acronym for the "digital imaging and communications in
medicine."standard for the process of recording, storing, printing, and transmitting
medical image data.
✔✔display field of view (DFOV) - ✔✔the diameter of the acquired attenuation data
displayed across the image matrix. may also be referred to as the zoom factor or target
view.
✔✔dose length product (DLP) - ✔✔the measurement of dose for the entire series of CT
images. equal to the calculated dose per section mulitplied by the length of a CT
acquisition along the z-axis.
AND SOLUTIONS RATED A+
✔✔bow-tie filter - ✔✔a type of filter added to the CT x-ray tube to compensate for the
cylindrical shape of most body parts. the filter is thicker at the ends and helps shape the
beam to reduce patient radiation exposure.
✔✔cardiac cycle - ✔✔the series of blood-flow related events that occur from the
beginning of one heartbeat to that of the next.
✔✔cerebral blood flow (CBF) - ✔✔a common measurement during CT perfusion studies
of the brain. CBF is the quantity of blood (mL) that moves through 100 g of brain tissue
each minute. normal range in gray matter is 50 to 60 mL/100 g/min
✔✔cerebral perfusion - ✔✔the level of blood flow throughout brain tissue.
✔✔constant mAs - ✔✔the product of milliamperage (mA) and scan time (seconds)
utilized for a CT acquisition.
✔✔contiguous images - ✔✔CT images acquired with equal section thickness and
reconstruction intervals
✔✔contrast resolution - ✔✔the ability of a CT system to detect an object with a small
difference in linear attenuation coefficient with the surrounding tissue. may also be
referred to as low-contrast detectability or sensitivity.
✔✔contrast-induced nephrotoxicity (CIN) - ✔✔a substantial decline in renal function that
can occur after a patient receives IV contrast material. it is usually signified by a marked
increase in serum creatinine over a baseline measurement obtained prior to contrast
agent administration.
✔✔convolution - ✔✔mathematical filatration used by the CT system to remove blurring
artifact during the back-projection method of image reconstruction
✔✔corticomedullary phase - ✔✔a late arterial phase of renal enhancement beginning
30 to 40 seconds after the initiation of contrast agent administration. optimal
enhancement of the renal cortex and renal veins occurs during this period.
✔✔creatinine - ✔✔a waste product of metabolism found in the bloodstream and
measured as an indicator of renal function. normal range is 0.5 to 1.5 mg/dL.
✔✔CT arthrography - ✔✔CT evaluation of a joint after the intra-articular injection of
iodinated contrast material.
,✔✔CT bronchography - ✔✔specialized MSCT examination of the tracheobronchial tree
consisting of MPR and volume-rendered 3D images reconstructed from thin,
overlapping MDCT axial images through the airways.
✔✔CT colonography - ✔✔specialized CT evaluation of the large intestine used primarily
for colon cancer screening. the large intestine is extended and scanned with thin-
section CT. 2D and 3D models are constructed, including virtual endoscopic fly-through
views.
✔✔CT dose index (CTDI) - ✔✔an approximate measure of the radiation dose received
in a single CT section or slice.
✔✔CT enteroclysis - ✔✔specialized CT evaluation of the small bowel whereby enteral
contrast material is administered directly into the duodenum through a nasogastric
catheter placed under fluoroscopic guidance.
✔✔CT enterography - ✔✔specialized CT evaluation of the small bowel after the oral
administration of low-density (0.1%) barium.
✔✔CT fluoroscopy - ✔✔continuous, real-time CT imagine used predominantly for CT
guided interventional procedures.
✔✔CT myelography - ✔✔Ct evaluation of the spinal cord and nerve roots after the
intrathecal administration of iodonated contrast material.
✔✔CT number - ✔✔relative value assinged to each pixel to quantify the attenuation
occurring in each voxel in comparison with the attenuation of water. Given in Hounsfield
units (HU) may also be referred to as pixel value.
✔✔CT runoff - ✔✔the CT angiographic assessment of the peripheral artierial tree from
the renal arteries through the lower extremeties.
✔✔CT simulation - ✔✔the process of obtaining anatomic information with CT imaging
that is used to calculate the beam arrangement for radiotherapy.
✔✔Ct urogram - ✔✔a comprehensive, multiphasic CT evaluation of the urinary tract.
consists primarily of pre-contrast, post-contrast, and delayed CT acquisitions through
the kidneys, ureters, and bladder. it may also be commonly referred to as a CT-IVP.
✔✔cupping artifact - ✔✔an error appearing in the superior portion of the skull, where
dense bone average with the low-attenuating brain tissue. this partial volume artifact
may result in abnormally dense-appearing brain parenchyma.
, ✔✔data acquisition system (DAS) - ✔✔the electronic components of a CT system
responsible for measuring the transmitted x-radiation absorbed by the detectors.
✔✔data channel - ✔✔pathway of data transmission from the detectors to the
computerized components of the system's data acquisition system. the number of
channels of a CT system determines the maximum number sections that may be
acquired with each gantry rotation.
✔✔data transer rate - ✔✔the speed at which computerized storage drive is able to
transer data
✔✔deconvolution - ✔✔mathematical image processing technique used to generate
blood perfusion maps during CT perfusion studies of the brain.
✔✔detector - ✔✔device responsible for measuring transmitted radiation and converting
it into a proportionate electronic signal to be used for image reconstruction.
✔✔detevtor array - ✔✔the CT image receptor, consisting of a series of detectors
arranged in varying configurations.
✔✔detector collimation - ✔✔the process of determining section width in the MSCT
system as determined by the defined beam width and the number and thickness of
detectors utilized for image reconstruction.
✔✔detector configuration - ✔✔the number, length, and organization of the individual
detector elements in an MSCT system
✔✔detector pitch - ✔✔the ratio of table feed per gantry rotation to the acquired section
width. this definition of pitch is used for helical single-slice CT (SSCT)
✔✔diastole - ✔✔portion of the cardiac cycle when the heart muscle is relaxed. it is the
bottom number provided during the assessment of blood pressure.
✔✔DICOM - ✔✔acronym for the "digital imaging and communications in
medicine."standard for the process of recording, storing, printing, and transmitting
medical image data.
✔✔display field of view (DFOV) - ✔✔the diameter of the acquired attenuation data
displayed across the image matrix. may also be referred to as the zoom factor or target
view.
✔✔dose length product (DLP) - ✔✔the measurement of dose for the entire series of CT
images. equal to the calculated dose per section mulitplied by the length of a CT
acquisition along the z-axis.
