Computed Tomography Exam Questions and Answers Latest Update 2025 Already Passed
what term is applied to a single square, or picture element, in the image display matrix - Answers pixel
what determines the amount of data displayed on the monitor - Answers field of view
a volume element is called - Answers voxel
a relative comparison of x-ray attenuation of a voxel of tissue to an equal volume of water - Answers CT
number
what is the CT number of water - Answers 0
the major system components of a CT scanner - Answers gantry
computer and operators console
patient table
a circular device that houses the x-ray tube, DAS, and detector array is called - Answers gantry
x-ray tubes used in advanced CT scanners can tolerate - Answers 4 to 5 MHU
these can be selected at the operators console - Answers slice thickness
table index
imaging technique factors
the range of CT numbers that are used to map signals into shades of gray is called - Answers window
width
the midpoint of the range of gray levels to be displayed on the monitor is the - Answers window level
a narrow window width would display - Answers high contrast
the window level should be set to - Answers the CT number of the tissue of interest
CT is the examination of choice for - Answers head trauma
the amount of blurring in a CT image is termed - Answers spatial resolution
the ability to differentiate between small differences in density within the CT image is called - Answers
contrast resolution
the most significant geometric factor that contributes to spatial resolution - Answers detector aperture
width
random variation in photon detection results in - Answers quantum noise
, these contribute to image noise in CT - Answers detector aperture width
matrix size
patient size
metallic objects, such as dental fillings can cause - Answers artifacts
high resolution CT scans are made using - Answers thinner sections or slices
which are quality factors affected by x-ray beam energy - Answers contrast resolution
noise
which image quality factor is affected by focal spot size - Answers spatial resolution
tissue density differences of less than ___ can be distinguished by CT - Answers .5%
reconstruction algorithm affects all of the image quality factors expect for - Answers artifacts
the image that appears o the monitor depends on the - Answers display field of view
what is based on the principle that different structures enhance at different rates after contrast
administration - Answers dynamic scanning
what new CT data acquisition method involves continuous gantry rotations combined with constant
table movement through the aperture - Answers spiral or helical CT
which 3-D imaging technique is commonly used for CTA - Answers maximum intensity projection
these are methods of 3-D reconstruction - Answers maximum intensity projection
volume rendering
shaded surface display
how often do most CT systems require preventive maintenance to ensure proper operation - Answers
weekly to biweekly
all of these affect radiation dose in CT - Answers beam energy
tube current
section/slice thickness
the anatomic scan range for a basic head CT is from the ____ to the ___ - Answers base of skull
vertex of head
what is the anatomic scan range for CT of the cervical spine - Answers occipital condyles to below T2
what term is applied to a single square, or picture element, in the image display matrix - Answers pixel
what determines the amount of data displayed on the monitor - Answers field of view
a volume element is called - Answers voxel
a relative comparison of x-ray attenuation of a voxel of tissue to an equal volume of water - Answers CT
number
what is the CT number of water - Answers 0
the major system components of a CT scanner - Answers gantry
computer and operators console
patient table
a circular device that houses the x-ray tube, DAS, and detector array is called - Answers gantry
x-ray tubes used in advanced CT scanners can tolerate - Answers 4 to 5 MHU
these can be selected at the operators console - Answers slice thickness
table index
imaging technique factors
the range of CT numbers that are used to map signals into shades of gray is called - Answers window
width
the midpoint of the range of gray levels to be displayed on the monitor is the - Answers window level
a narrow window width would display - Answers high contrast
the window level should be set to - Answers the CT number of the tissue of interest
CT is the examination of choice for - Answers head trauma
the amount of blurring in a CT image is termed - Answers spatial resolution
the ability to differentiate between small differences in density within the CT image is called - Answers
contrast resolution
the most significant geometric factor that contributes to spatial resolution - Answers detector aperture
width
random variation in photon detection results in - Answers quantum noise
, these contribute to image noise in CT - Answers detector aperture width
matrix size
patient size
metallic objects, such as dental fillings can cause - Answers artifacts
high resolution CT scans are made using - Answers thinner sections or slices
which are quality factors affected by x-ray beam energy - Answers contrast resolution
noise
which image quality factor is affected by focal spot size - Answers spatial resolution
tissue density differences of less than ___ can be distinguished by CT - Answers .5%
reconstruction algorithm affects all of the image quality factors expect for - Answers artifacts
the image that appears o the monitor depends on the - Answers display field of view
what is based on the principle that different structures enhance at different rates after contrast
administration - Answers dynamic scanning
what new CT data acquisition method involves continuous gantry rotations combined with constant
table movement through the aperture - Answers spiral or helical CT
which 3-D imaging technique is commonly used for CTA - Answers maximum intensity projection
these are methods of 3-D reconstruction - Answers maximum intensity projection
volume rendering
shaded surface display
how often do most CT systems require preventive maintenance to ensure proper operation - Answers
weekly to biweekly
all of these affect radiation dose in CT - Answers beam energy
tube current
section/slice thickness
the anatomic scan range for a basic head CT is from the ____ to the ___ - Answers base of skull
vertex of head
what is the anatomic scan range for CT of the cervical spine - Answers occipital condyles to below T2
