MOSBY'S CT COMPREHENSIVE EXAM 2026 QUESTIONS
AND SOLUTIONS RATED A+
✔✔hybrid-array - ✔✔the type of MSCT detector array with narrower detectors
positioned midline, flanked by the wider detectors.
✔✔hyperdense - ✔✔possessing CT attenuation values greater than the values of the
surrounding tissue.
✔✔hypodense - ✔✔possessing CT attenuation values less than the values of the
surrounding tissue.
✔✔image compression - ✔✔complex computer technique that reduces the size of
digital CT image data.
✔✔image data - ✔✔the reconstructed data that have been projected back onto a matrix
after convolution by an algorithm and displayed on a monitor as a gray-scale CT image.
✔✔insufflation - ✔✔the introduction of air into an organ or cavity for distention and
improved visualization.
✔✔interpolation - ✔✔the mathematical process used for helical CT image
reconstruction whereby data from tube rotation just above and just below a given slice
position are used for image reconstruction.
✔✔isocenter - ✔✔the center point of gantry rotation
✔✔isodense - ✔✔possessing CT attenuation values equal to the values of the
surrounding tissue.
✔✔isotropic - ✔✔having equal dimensions along the x-,y-, and z-axes; in CT, describes
voxels with this property.
✔✔kerma - ✔✔quantity of energy deposited in a unit of mass. used to describe the
absorbed dose of x-radiation.
✔✔kernal - ✔✔mathematical filter applied to raw data during CT image reconstruction to
remove the blurring artifact inherent to back-projection. also referred to as an algorithm.
✔✔linear attenuation coefficient - ✔✔the value assigned to an object to quantify the
extent to which it attenuates x-ray.
✔✔linearity - ✔✔the relative accuracy between calculated CT numbers and their
respective linear attenuation coefficients.
, ✔✔lossless compression - ✔✔the reversible process whereby the CT image is digitally
compress in size without loss of data and is identical to the original.
✔✔lossy compression - ✔✔the irreversible process whereby data are lossed during the
compression process and the CT image does not exactly match the original.
✔✔matrix - ✔✔two-dimensional grid of numbers arranged in rows and columns.
✔✔maximum ontensity projection (MIP) - ✔✔multiplanar reformation technique that
displays only the maximum pixel value along a ray traced through the object to the
viewer's assumed perspective in front of the viewing monitor.
✔✔means transit time (MTT) - ✔✔a common measurement during CT perfusion studies
of the brain. refers to the average transit time, in seconds, needed for blood to pass
through a given region of brain tissue.
✔✔minimum intensity projection (mini-IP) - ✔✔multiplanar reformation technique that
displays the minimm pixel values along each ray to the viewer.
✔✔misregistration - ✔✔artifact the occurs when patient motion between consecutive
acquisitions causes mis-alignement of data and the potentional loss of anatomic
information.
✔✔modulation transer function (MTF) - ✔✔a graphical representation of a CT system's
response to a spacial frequency that serves as a measurement of the system's in-plane
spacial resolution.
✔✔monoenergetic - ✔✔consisting of a uniform photon energy; used in CT to describe a
beam of x-radiation.
✔✔multi-slice CT (MSCT) - ✔✔a CT system with a detector array capable of acquiring
more than one section for each gantry rotation. also referred to as multidetector CT
(MDCT)
✔✔mulitphase - ✔✔CT data acquisition during mulitple timed phases of contrast
enhancement.
✔✔multiplanar reformation (MPR) - ✔✔the process of displaying CT images in a
different orientation from the one used in the original reconstruction.
✔✔multiple scan average dose (MSAD) - ✔✔a calculation of the average cumulative
radiation dose to each anatomic slice within the center of a CT scan consisting of
multiple slices.
AND SOLUTIONS RATED A+
✔✔hybrid-array - ✔✔the type of MSCT detector array with narrower detectors
positioned midline, flanked by the wider detectors.
✔✔hyperdense - ✔✔possessing CT attenuation values greater than the values of the
surrounding tissue.
✔✔hypodense - ✔✔possessing CT attenuation values less than the values of the
surrounding tissue.
✔✔image compression - ✔✔complex computer technique that reduces the size of
digital CT image data.
✔✔image data - ✔✔the reconstructed data that have been projected back onto a matrix
after convolution by an algorithm and displayed on a monitor as a gray-scale CT image.
✔✔insufflation - ✔✔the introduction of air into an organ or cavity for distention and
improved visualization.
✔✔interpolation - ✔✔the mathematical process used for helical CT image
reconstruction whereby data from tube rotation just above and just below a given slice
position are used for image reconstruction.
✔✔isocenter - ✔✔the center point of gantry rotation
✔✔isodense - ✔✔possessing CT attenuation values equal to the values of the
surrounding tissue.
✔✔isotropic - ✔✔having equal dimensions along the x-,y-, and z-axes; in CT, describes
voxels with this property.
✔✔kerma - ✔✔quantity of energy deposited in a unit of mass. used to describe the
absorbed dose of x-radiation.
✔✔kernal - ✔✔mathematical filter applied to raw data during CT image reconstruction to
remove the blurring artifact inherent to back-projection. also referred to as an algorithm.
✔✔linear attenuation coefficient - ✔✔the value assigned to an object to quantify the
extent to which it attenuates x-ray.
✔✔linearity - ✔✔the relative accuracy between calculated CT numbers and their
respective linear attenuation coefficients.
, ✔✔lossless compression - ✔✔the reversible process whereby the CT image is digitally
compress in size without loss of data and is identical to the original.
✔✔lossy compression - ✔✔the irreversible process whereby data are lossed during the
compression process and the CT image does not exactly match the original.
✔✔matrix - ✔✔two-dimensional grid of numbers arranged in rows and columns.
✔✔maximum ontensity projection (MIP) - ✔✔multiplanar reformation technique that
displays only the maximum pixel value along a ray traced through the object to the
viewer's assumed perspective in front of the viewing monitor.
✔✔means transit time (MTT) - ✔✔a common measurement during CT perfusion studies
of the brain. refers to the average transit time, in seconds, needed for blood to pass
through a given region of brain tissue.
✔✔minimum intensity projection (mini-IP) - ✔✔multiplanar reformation technique that
displays the minimm pixel values along each ray to the viewer.
✔✔misregistration - ✔✔artifact the occurs when patient motion between consecutive
acquisitions causes mis-alignement of data and the potentional loss of anatomic
information.
✔✔modulation transer function (MTF) - ✔✔a graphical representation of a CT system's
response to a spacial frequency that serves as a measurement of the system's in-plane
spacial resolution.
✔✔monoenergetic - ✔✔consisting of a uniform photon energy; used in CT to describe a
beam of x-radiation.
✔✔multi-slice CT (MSCT) - ✔✔a CT system with a detector array capable of acquiring
more than one section for each gantry rotation. also referred to as multidetector CT
(MDCT)
✔✔mulitphase - ✔✔CT data acquisition during mulitple timed phases of contrast
enhancement.
✔✔multiplanar reformation (MPR) - ✔✔the process of displaying CT images in a
different orientation from the one used in the original reconstruction.
✔✔multiple scan average dose (MSAD) - ✔✔a calculation of the average cumulative
radiation dose to each anatomic slice within the center of a CT scan consisting of
multiple slices.
