Has Risk for Contrast-Induced Nephropathy Been Exaggerated?

Conventional wisdom — supported largely by inadequately controlled observational studies — holds that patients with even modestly abnormal renal function are vulnerable to contrast-induced nephropathy. Presumed causes include direct renal toxicity and intrarenal hemodynamic effects of contrast media. In 2014, Mayo Clinic researchers published two studies that challenged the importance of contrast-induced nephropathy after computed tomography (CT) scanning.

The researchers drew from a database of patients who underwent chest, abdominal, or pelvic CT scanning. Using propensity scoring, they created two cohorts, each with 6245 patients: One group had undergone intravenous contrast-enhanced CT, and the other had undergone unenhanced CT, but the …