Scan Protocols Flashcards
7 cards from real ARRT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Scan Protocols flashcards as text
Which scan parameter adjustment would best reduce streak artifact from dental fillings on a head/neck CT?
Answer: Use gantry tilt to avoid the plane of the fillings
Tilting the gantry angles the scan plane away from dense dental hardware, reducing the metal streak artifact through structures of interest.
In a CT perfusion study of the brain, which parameter measures the volume of blood in a given unit of brain tissue?
Answer: Cerebral blood volume (CBV)
Cerebral blood volume (CBV) represents the total volume of blood within a defined brain tissue volume, measured in mL/100g.
For a CT of the paranasal sinuses ordered to guide functional endoscopic sinus surgery (FESS), which plane is most critical for the surgeon?
Answer: Coronal plane
The coronal plane directly depicts the ostiomeatal complex, sinus drainage pathways, and the relationship to the orbit and skull base — essential for FESS planning.
When a CT abdomen protocol specifies 'nephrographic phase,' scanning typically occurs at what delay after IV contrast injection?
Answer: 80–120 seconds
The nephrographic phase occurs at approximately 80–120 seconds post-injection when both cortex and medulla enhance uniformly, optimizing renal parenchymal visualization.
A CT scan protocol using 'prospective ECG gating' for cardiac imaging acquires data only during which part of the cardiac cycle?
Answer: Only during a pre-selected phase of diastole
Prospective ECG gating triggers X-ray exposure only during a selected quiescent diastolic window, substantially reducing radiation dose compared to retrospective gating.
Which of the following scan coverage ranges is standard for a CT of the abdomen and pelvis?
Answer: Diaphragm to pubic symphysis
A standard abdomen and pelvis CT extends from the diaphragm superiorly to the pubic symphysis inferiorly to cover all abdominal and pelvic organs.
Which of the following is the primary reason for using a low-osmolar, non-ionic iodinated contrast agent for intravenous CT contrast?
Answer: It significantly reduces the risk of adverse reactions compared to ionic agents
Non-ionic, low-osmolar contrast agents have a much lower rate of adverse reactions (including severe reactions) compared to older high-osmolar ionic agents.