CT Contrast Media and Patient Preparation Flashcards
6 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 6 CT Contrast Media and Patient Preparation flashcards as text
What is the most common type of iodinated contrast media used for CT examinations?
Answer: Non-ionic, water-soluble iodinated contrast
Non-ionic, water-soluble iodinated contrast agents are preferred for CT because they have lower osmolality and fewer adverse reactions compared to ionic agents.
Which serum creatinine-based calculation is most commonly used to screen for contrast-induced nephropathy risk before CT?
Answer: eGFR (estimated Glomerular Filtration Rate)
eGFR calculated from serum creatinine is the standard screening tool; an eGFR <30 mL/min/1.73m² generally indicates high risk for contrast nephrotoxicity.
At what injection rate (mL/sec) is intravenous contrast typically administered for a CT pulmonary angiography (CTPA)?
Answer: 3–5 mL/sec
CTPA requires a brisk injection rate of 3–5 mL/sec to achieve adequate pulmonary artery opacification during the brief arterial phase.
Which medication must be withheld 48 hours before and after iodinated contrast administration in patients with renal impairment?
Answer: Metformin
Metformin must be withheld because contrast-induced nephropathy can impair its renal clearance, leading to toxic accumulation and risk of lactic acidosis.
What is the typical oral contrast agent used to opacify the GI tract during abdominal CT?
Answer: Dilute barium or water-soluble iodinated contrast
Dilute barium sulfate or water-soluble iodinated contrast is given orally to distend and opacify the bowel, distinguishing it from adjacent pathology.
Which phase of contrast enhancement is best for evaluating hypervascular liver tumors such as hepatocellular carcinoma (HCC)?
Answer: Arterial phase (25–35 seconds post-injection)
HCC derives its blood supply primarily from the hepatic artery and enhances dramatically during the arterial phase, a hallmark feature used for diagnosis.