1. What is the primary disadvantage of CT imaging when compared to
MRI?
A. CT scans are more expensive than MRIs
B. CT imaging cannot visualize soft tissues as well as MRI
C. CT scanning takes longer than MRI
D. CT imaging cannot be used for abdominal scans
Answer: B) CT imaging cannot visualize soft tissues as well as MRI
Rationale: MRI generally provides better soft tissue contrast than CT,
making it more suitable for imaging the brain, spinal cord, and muscles,
whereas CT is better for detecting bone and calcified structures.
2. What is the typical appearance of a lung with emphysema on a CT
scan?
A. Increased attenuation with white areas
B. Decreased attenuation with dark areas
C. Sharp boundary between lung and surrounding tissues
D. Nodules within the lung parenchyma
Answer: B) Decreased attenuation with dark areas
Rationale: In emphysema, the lung tissue is destroyed, leading to areas
of decreased density, which appear dark on a CT scan due to reduced
tissue attenuation.
,3. What is the purpose of using a contrast agent in a CT scan?
A. To reduce the exposure to radiation
B. To make the blood vessels and certain organs more visible
C. To enhance the scanning process and reduce artifacts
D. To correct for motion during the scan
Answer: B) To make the blood vessels and certain organs more visible
Rationale: Contrast agents, typically iodine-based, are used in CT scans
to improve the visibility of blood vessels, soft tissues, and organs,
enhancing the ability to detect abnormalities.
4. What does the term "window width" refer to in CT imaging?
A. The size of the imaging field
B. The range of CT numbers displayed
C. The thickness of the slice
D. The angle of the X-ray beam
Answer: B) The range of CT numbers displayed
Rationale: "Window width" controls the range of Hounsfield units (CT
numbers) displayed on the image. A narrow window width increases
contrast, while a wide window width can display a broader range of
densities, such as those of various soft tissues.
, 5. What is the main purpose of using a "post-processing" technique in
CT imaging?
A. To add contrast to soft tissue
B. To increase the radiation dose to the patient
C. To improve the quality of the final image through software
adjustments
D. To reduce the slice thickness of the scan
Answer: C) To improve the quality of the final image through software
adjustments
Rationale: Post-processing techniques enhance CT images after the
scan is complete by adjusting contrast, removing artifacts, or
reformatting images for better diagnosis.
6. Which of the following organs or tissues has the highest attenuation
on a CT scan?
A. Bone
B. Fat
C. Liver
D. Air
Answer: A) Bone
Rationale: Bone has a high attenuation on a CT scan because it absorbs
more X-rays compared to other tissues. This results in it appearing
white or bright on the scan images.
MRI?
A. CT scans are more expensive than MRIs
B. CT imaging cannot visualize soft tissues as well as MRI
C. CT scanning takes longer than MRI
D. CT imaging cannot be used for abdominal scans
Answer: B) CT imaging cannot visualize soft tissues as well as MRI
Rationale: MRI generally provides better soft tissue contrast than CT,
making it more suitable for imaging the brain, spinal cord, and muscles,
whereas CT is better for detecting bone and calcified structures.
2. What is the typical appearance of a lung with emphysema on a CT
scan?
A. Increased attenuation with white areas
B. Decreased attenuation with dark areas
C. Sharp boundary between lung and surrounding tissues
D. Nodules within the lung parenchyma
Answer: B) Decreased attenuation with dark areas
Rationale: In emphysema, the lung tissue is destroyed, leading to areas
of decreased density, which appear dark on a CT scan due to reduced
tissue attenuation.
,3. What is the purpose of using a contrast agent in a CT scan?
A. To reduce the exposure to radiation
B. To make the blood vessels and certain organs more visible
C. To enhance the scanning process and reduce artifacts
D. To correct for motion during the scan
Answer: B) To make the blood vessels and certain organs more visible
Rationale: Contrast agents, typically iodine-based, are used in CT scans
to improve the visibility of blood vessels, soft tissues, and organs,
enhancing the ability to detect abnormalities.
4. What does the term "window width" refer to in CT imaging?
A. The size of the imaging field
B. The range of CT numbers displayed
C. The thickness of the slice
D. The angle of the X-ray beam
Answer: B) The range of CT numbers displayed
Rationale: "Window width" controls the range of Hounsfield units (CT
numbers) displayed on the image. A narrow window width increases
contrast, while a wide window width can display a broader range of
densities, such as those of various soft tissues.
, 5. What is the main purpose of using a "post-processing" technique in
CT imaging?
A. To add contrast to soft tissue
B. To increase the radiation dose to the patient
C. To improve the quality of the final image through software
adjustments
D. To reduce the slice thickness of the scan
Answer: C) To improve the quality of the final image through software
adjustments
Rationale: Post-processing techniques enhance CT images after the
scan is complete by adjusting contrast, removing artifacts, or
reformatting images for better diagnosis.
6. Which of the following organs or tissues has the highest attenuation
on a CT scan?
A. Bone
B. Fat
C. Liver
D. Air
Answer: A) Bone
Rationale: Bone has a high attenuation on a CT scan because it absorbs
more X-rays compared to other tissues. This results in it appearing
white or bright on the scan images.
