Questions and CORRECT Answers
Helical scanning motion was first made possible by the unique construction of the
____________ scanner.
A) fourth generation B) fifth generation C) sixth generation D) seventh generation - CORRECT
ANSWER - 7th
The type of beam geometry used in modern CT scanners is called:
A) fan beam. B) wide beam. C) pencil beam. D) cone beam. - CORRECT ANSWER -
cone beam
The ___________ method of data acquisition gathers image data in distinct sections and is
sometimes describes as having a "start/stop" motion.
A) spiral B) sequential C) helical D) volume - CORRECT ANSWER - sequential
When pitch is less than 1, the resulting bands of data are:
A) adjacent. B) distinct. C) overlapped. D) gapped - CORRECT ANSWER - overlapping
Which of the following is not a component of the CT gantry?
A) X-ray tube B) Array processor C) Slip rings D) Digital acquisition system - CORRECT
ANSWER - array processor
Detector systems in which the elements are not all the same size are referred to as:
A) adaptive arrays. B) volumetric arrays. C) symmetric arrays. D) unbalanced arrays. -
CORRECT ANSWER - adaptive arrays
All of the following are characteristics of beam-shaping filters, except:
A) they are physical devices.
B) they change the spatial distribution of the beam.
,C) they change the digital appearance of images.
D) they remove lower-energy x-rays from the beam. - CORRECT ANSWER - they change
digital appearance of images
The primary data processing component of the CT system is the:
A) array processor. B) digital acquisition system. C) PACS. D) amplifier. - CORRECT
ANSWER - array processor
An increase in pitch also results in increased:
A) patient dose. B) scan speed. C) image quality. D) scan length. - CORRECT ANSWER -
scan speed
The largest piece of the CT device is called:
A) the gantry. B) the processor. C) the housing. D) the ring. - CORRECT ANSWER -
gantry
When considering detector efficiency, the measure of how consistently the detectors respond is
called:
A) capture efficiency. B) absorption efficiency. C) stability. D) response time. - CORRECT
ANSWER - stability
Which component of the CT gantry supplies electrical power to the x-ray tube and transfers the
signals from the detectors to the computer?
A) Generator B) Slip rings C) Photomultiplier D) Data acquisition system - CORRECT
ANSWER - slip rings
The first generation CT scan pattern was called _______ acquisition.
A) translate and rotate B) step-and-shoot C) helical D) linear - CORRECT ANSWER -
translate and rotate
, Which of the following is false regarding conventional axial scanning compared to helical
scanning?
A) Axial scanning requires more contrast media.
B) Axial scanning has greater potential for misalignment between scans.
C) Axial scanning is more sensitive to patient motion.
D) Axial scanning results in poorer image quality. - CORRECT ANSWER - more sensitive
to patient motion
The number of detectors the scanner uses to collect data for a particular scan is determined by
the:
A) scan field of view. B) display field of view. C) pitch. D) slice thickness. - CORRECT
ANSWER - SFOV
Using a wider display field of view results in:
A) reduced noise. B) improved spatial resolution. C) anatomy appearing larger. D) increased
patient dose. - CORRECT ANSWER - reduced noise
The depth of a voxel is determined by the:
A) field of view. B) slice thickness. C) matrix size. D) pixel size. - CORRECT ANSWER -
slice thickness
The range of CT numbers displayed in the reconstructed image is controlled by:
A) subject contrast. B) inherent contrast C) window width. D) window level. - CORRECT
ANSWER - window width
All of the following types of exams typically use a large SFOV, except for:
A) chest exams. B) spine exams. C) extremity exams. D) skull exams. - CORRECT
ANSWER - skull
Matrix size never changes, but the pixel size can vary based on the selected: A) scan field of
view. B) pitch. C) kVp. D) mAs. - CORRECT ANSWER - SFOV