Computed Tomography Knowledge Questions and An 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 Knowledge Questions and An flashcards as text
Which windowing preset is most appropriate for evaluating pulmonary nodules on CT?
Answer: Lung window (W:1500, L:-600)
Lung window settings (wide width, negative level) optimize contrast for air-filled lung parenchyma and nodule detection.
What is the primary advantage of dual-energy CT (DECT) over single-energy CT?
Answer: Ability to characterize tissue composition based on material decomposition
DECT acquires data at two energy levels, enabling material decomposition to distinguish substances like iodine, uric acid, and calcium.
A CT scan shows an adrenal lesion with an unenhanced attenuation of 8 HU. What is the most likely diagnosis?
Answer: Adrenal adenoma
Adrenal lesions with unenhanced HU ≤10 are consistent with lipid-rich adenomas due to intracellular fat content.
What does the term 'partial volume averaging' refer to in CT imaging?
Answer: Blending of attenuation values from different tissues within a single voxel
Partial volume averaging occurs when a voxel contains more than one tissue type, resulting in an averaged attenuation value that misrepresents both tissues.
Which reconstruction algorithm produces sharper edges but increased image noise in CT?
Answer: Bone/sharp kernel
Sharp (bone) kernels apply high-frequency enhancement to improve edge definition, which amplifies noise compared to smooth kernels.
In CT angiography, what is the purpose of a test bolus or bolus tracking technique?
Answer: To optimize scan timing relative to contrast arrival in the target vessel
Bolus tracking and test bolus methods synchronize scan initiation with peak contrast enhancement in the target vessel to ensure optimal opacification.
What is the typical scan direction for most helical CT acquisitions?
Answer: Superior to inferior
Most helical CT acquisitions proceed from superior to inferior (craniocaudal), though specific protocols may vary for certain applications like runoff studies.