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%

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
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preliminary/localizer image taken at the start of a CT examinati
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on?
A. Topogram
,




B. Scout
,




C. Scanogram
,




D. Spiral
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2. The ability of a system to differentiate, on the image, objects wi
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th similar densities is known as:
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A. High contrast resolution
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B. Low contrast resolution
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C. Spatial resolution
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D. Temporal resolution
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,3. Each two dimensional square of data that make up the CT ima
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ge is called a:
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A. Pixel
,




B. Voxel
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C. Matrix
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D. Fragment
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4. How many pixels are contained in a 1,024 matrix image?
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A. 1,024
,




B. 2,048
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C. 262,144
,




D. 1,048,576
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5. Beam attenuation can be defined as: , , , , ,




A. The phenomenon by which artifacts result when lower energy pho
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tons are preferentially absorbed, leaving only higher-
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intensity photons to strike the detector array.
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B. Xray energy that is produced from bombarding a substance with fa
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st moving electrons.
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C. The ability of the detector to capture transmitted photons and chan
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ge them to electronic signals.
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D. The phenomenon by which an xray beam passing through a struct
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ure is decreased in intensity or amount because of absorption and inte
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raction with matter. ANS: D. The phenomenon by which an xray
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beam passing through a structure is decreased in intensity or amount
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because of absorption and interaction with matter.
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,6. Which of the following is a low attenuation structure:
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A. Iodine filled aorta
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B. Rib ,




C. Trachea
,




D. Calcified arteries
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7. An object is slightly less dense than water. What is the expected
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hounsfield measurement?
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A. -940 ,




B. -10 ,




C. 50 ,




D. 850 , ,,,,,,,,,, ANS: B. -10 ,,, ,




8. Why does the administration of iodinated contrast media resul
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t in an enhanced image?
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A. Iodinated contrast material increases the ability of the enhanced st
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ructure to attenuate the xray beam. , , , , ,




B. Iodinated contrast material decreases the average photon energy o
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f the xray beam; therefore more photons are absorbed by the patient.
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C. The administration of contrast material results in a smaller pixel, t
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hereby increasing spatial resolution, which results in an enhanced im
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age. ANS: A. Iodinated contrast material increases the ability of t
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he enhanced structure to attenuate the xray beam.
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, 9. The xray beam sources for CT produce xray energy that is pol
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ychromatic. This means: , ,




A. When viewed by the naked eye, the beam exhibits many different
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colors.
B. It produce, as a byproduct, a substance known as polychlorinated b
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iphenyl.
C. Photons contained in the beam are all of the same wavelength.
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D. The beam comprises photons with varying energies.
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The beam comprises photons with varying energies.
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10. An object that appears on the image but is not present in the o
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bject scanned is called a/n:
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A. Artifact
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B. Anomaly
,




C. Shadow
,




D. Ghost
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11. Which is an advantage of filtering the xray beam?
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A. Filtering reduces the anode heat load
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B. A filtered beam produces images with substantially less quantum
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mottle
C. Filtering the beam prevents energy from being converted to heat, t
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herefore 100% of the energy is converted to xrays.
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D. Filtering reduces the radiation dose to the patient.
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tering reduces the radiation dose to the patient
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