CT TEST REVIEW (TEST Q'S AND A'S FOR CT
REGISTRY PREP. THIS IS FROM THE BOOK
"COMPUTED TOMOGRAPHY FOR
TECHNOLOGISTS: EXAM REVIEW" BY LOIS E
ROMANS. PUBLISHED BY WOLTERS KLUWER,
LIPPINCOTT WILLIAMS AND WILKINS.)
QUESTIONS & ANSWERS RATED 100% C
1. Which is NOT a synonym for the
, , , , , ,
preliminary/localizer image taken at the start of a CT examinati
, , , , , , , , , ,
on?
A. Topogram
,
B. Scout
,
C. Scanogram
,
D. Spiral
, ,,,,,,,,,, ANS: D. Spiral ,,, ,
2. The ability of a system to differentiate, on the image, objects wi
, , , , , , , , , , ,
th similar densities is known as:
, , , , ,
A. High contrast resolution
, , ,
B. Low contrast resolution
, , ,
C. Spatial resolution
, ,
D. Temporal resolution
, , ,,,,,,,,,, ANS: B. Low contrast resolution
,,, , , ,
,3. Each two dimensional square of data that make up the CT ima
, , , , , , , , , , ,
ge is called a:
, , ,
A. Pixel
,
B. Voxel
,
C. Matrix
,
D. Fragment
, ,,,,,,,,,, ANS: A. Pixel ,,, ,
4. How many pixels are contained in a 1,024 matrix image?
, , , , , , , , , ,
A. 1,024
,
B. 2,048
,
C. 262,144
,
D. 1,048,576
, ,,,,,,,,,, ANS: D. 1,048,576 ,,, ,
5. Beam attenuation can be defined as: , , , , ,
A. The phenomenon by which artifacts result when lower energy pho
, , , , , , , , , ,
tons are preferentially absorbed, leaving only higher-
, , , , , ,
intensity photons to strike the detector array.
, , , , , ,
B. Xray energy that is produced from bombarding a substance with fa
, , , , , , , , , , ,
st moving electrons.
, ,
C. The ability of the detector to capture transmitted photons and chan
, , , , , , , , , , ,
ge them to electronic signals.
, , , ,
D. The phenomenon by which an xray beam passing through a struct
, , , , , , , , , , ,
ure is decreased in intensity or amount because of absorption and inte
, , , , , , , , , , ,
raction with matter. ANS: D. The phenomenon by which an xray
, , ,,,,,,,,,, ,,, , , , , , , ,
beam passing through a structure is decreased in intensity or amount
, , , , , , , , , , ,
because of absorption and interaction with matter.
, , , , , ,
,6. Which of the following is a low attenuation structure:
, , , , , , , ,
A. Iodine filled aorta
, , ,
B. Rib ,
C. Trachea
,
D. Calcified arteries
, , ,,,,,,,,,, ANS: C. Trachea ,,, ,
7. An object is slightly less dense than water. What is the expected
, , , , , , , , , , ,
hounsfield measurement?
, ,
A. -940 ,
B. -10 ,
C. 50 ,
D. 850 , ,,,,,,,,,, ANS: B. -10 ,,, ,
8. Why does the administration of iodinated contrast media resul
, , , , , , , ,
t in an enhanced image?
, , , ,
A. Iodinated contrast material increases the ability of the enhanced st
, , , , , , , , , ,
ructure to attenuate the xray beam. , , , , ,
B. Iodinated contrast material decreases the average photon energy o
, , , , , , , , ,
f the xray beam; therefore more photons are absorbed by the patient.
, , , , , , , , , , ,
C. The administration of contrast material results in a smaller pixel, t
, , , , , , , , , , ,
hereby increasing spatial resolution, which results in an enhanced im
, , , , , , , , ,
age. ANS: A. Iodinated contrast material increases the ability of t
,,,,,,,, ,,, , , , , , , , ,
he enhanced structure to attenuate the xray beam.
, , , , , , ,
, 9. The xray beam sources for CT produce xray energy that is pol
, , , , , , , , , , ,
ychromatic. This means: , ,
A. When viewed by the naked eye, the beam exhibits many different
, , , , , , , , , , , ,
colors.
B. It produce, as a byproduct, a substance known as polychlorinated b
, , , , , , , , , , ,
iphenyl.
C. Photons contained in the beam are all of the same wavelength.
, , , , , , , , , , ,
D. The beam comprises photons with varying energies.
, , , , , , , ,,,,,,,,,, ANS: D. ,,, ,
The beam comprises photons with varying energies.
, , , , , ,
10. An object that appears on the image but is not present in the o
, , , , , , , , , , , , ,
bject scanned is called a/n:
, , , ,
A. Artifact
,
B. Anomaly
,
C. Shadow
,
D. Ghost
, ,,,,,,,,,, ANS: A. Artifact ,,, ,
11. Which is an advantage of filtering the xray beam?
, , , , , , , ,
A. Filtering reduces the anode heat load
, , , , , ,
B. A filtered beam produces images with substantially less quantum
, , , , , , , , , ,
mottle
C. Filtering the beam prevents energy from being converted to heat, t
, , , , , , , , , , ,
herefore 100% of the energy is converted to xrays.
, , , , , , , ,
D. Filtering reduces the radiation dose to the patient.
, , , , , , , , ,,,,,,,,,, ANS: D. Fil ,,, ,
tering reduces the radiation dose to the patient
, , , , , , ,
