Computed Tomography Ultimate Flashcards
7 cards from real Computed Tomography Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Computed Tomography Ultimate flashcards as text
What is the typical radiation dose range for a standard adult abdomen-pelvis CT examination?
Answer: 8-15 mSv
A standard adult abdomen-pelvis CT delivers approximately 8-15 mSv effective dose, significantly higher than chest X-ray but providing much greater diagnostic information.
Which reconstruction filter (kernel) would be most appropriate for evaluating fine bony detail in CT?
Answer: Sharp/bone kernel
Sharp or bone kernels enhance high-frequency information (edges) at the cost of increased noise, making fine bony trabecular and cortical detail more visible.
What is the significance of the 'z-flying focal spot' technology in multidetector CT?
Answer: It doubles the number of effective slices by alternating focal spot positions along the z-axis
Z-flying focal spot alternates the focal spot between two positions along the z-axis within each rotation, doubling the number of independently acquired slices and improving z-axis resolution.
A patient presents with an allergy to shellfish. What is the appropriate clinical management before administering iodinated contrast?
Answer: Shellfish allergy alone is not a reliable predictor; assess for prior contrast reactions specifically
Shellfish allergy is a common misconception as a predictor of contrast allergy; the true risk factor is a prior reaction to iodinated contrast media specifically.
In CT perfusion imaging of the brain, which parameter best reflects the integrity of cerebral autoregulation?
Answer: Cerebral blood volume (CBV)
Cerebral blood volume (CBV) reflects the total volume of blood in a given brain region and is maintained by autoregulation; preserved CBV with reduced CBF indicates penumbral tissue.
What is the primary advantage of using a low kVp technique in CT pulmonary angiography (CTPA)?
Answer: Increases contrast enhancement due to photoelectric effect near iodine's K-edge
Lower kVp (e.g., 80-100 kVp) increases iodine conspicuity because the beam energy is closer to iodine's K-edge (~33 keV), enhancing the photoelectric effect and boosting contrast.
Which parameter describes the relationship between table travel per gantry rotation and total beam collimation in helical CT?
Answer: Pitch
Pitch is defined as table distance traveled per 360° rotation divided by the total nominal beam collimation width; values >1 indicate gaps in data and values <1 indicate overlap.