Risk Assessment & Management Flashcards

A patient is scheduled for a contrast-enhanced CT but reports a serum creatinine of 1.8 mg/dL. This finding primarily raises concern for:

Answer: Contrast-induced nephropathy (CIN)

An elevated serum creatinine indicates reduced renal function, increasing the risk of contrast-induced nephropathy (CIN). The radiologist must evaluate the risk-benefit ratio and may order hydration protocols or consider alternatives.

Which of the following best describes the radiation risk concept of 'stochastic effects'?

Answer: Probabilistic effects (cancer/genetic mutations) whose probability increases with dose but severity does not

Stochastic effects (cancer and heritable genetic mutations) have no dose threshold — even small doses carry a probability of occurrence. The probability increases with dose but the severity of the effect (if it occurs) is independent of dose.

A patient's medical history reveals they are taking metformin for type 2 diabetes. What is the primary concern when iodinated contrast is planned?

Answer: Risk of lactic acidosis if contrast-induced nephropathy develops

Metformin is associated with lactic acidosis — a rare but life-threatening complication — if excreted renally and renal function deteriorates (e.g., due to CIN). Standard protocol is to hold metformin at the time of contrast administration and for 48 hours afterward.

The 10-day rule for radiographic examination of the abdomen and pelvis in women of childbearing age is designed to:

Answer: Minimize the chance of irradiating an early unrecognized pregnancy

The 10-day rule (now largely superseded by ALARA principles) historically recommended scheduling abdominal/pelvic X-rays in the first 10 days after menstruation, when pregnancy is unlikely. Modern practice uses pregnancy screening questions instead.

Which of the following is a major risk factor for developing a venous thromboembolism (VTE) in patients undergoing lengthy radiologic procedures?

Answer: Prolonged immobility during the procedure

Prolonged immobility is a major risk factor for VTE (deep vein thrombosis and pulmonary embolism) because venous stasis promotes clot formation. Long interventional radiology procedures require VTE risk assessment and prophylaxis planning.

Which imaging modality is considered safest for imaging a pregnant patient when the clinical question requires cross-sectional imaging?

Answer: MRI without gadolinium contrast

MRI without gadolinium contrast is the preferred cross-sectional imaging modality in pregnancy because it does not use ionizing radiation. Gadolinium crosses the placenta and is avoided in the first trimester; CT and nuclear medicine involve ionizing radiation.