VANCOUVER, BC—Computed tomography (CT) scans using contrast media are associated with a minimal risk of contrast-induced nephropathy (CIN), researchers reported at the Canadian Society of Nephrology 2014 annual meeting.
Michael Garfinkle, MD, and colleagues at the University of Saskatchewan in Saskatoon, analyzed the incidence of CIN associated with 2,583 CT scans with contrast performed on 2,277 unique patients. They compared the incidence of acute kidney injury (AKI) immediately after contrast administration and then a few days afterward in the same patients.
They also corrected for creatinine kinetics by considering an AKI occurring prior to a CT scan and leading to a creatinine rise continuing after the CT scan not to be associated with the scan itself.The difference between the incidence of the immediate post-scan and delayed post-scan AKI was assumed to be the risk of AKI attributable to the imaging study.
Dr. Garfinkle’s group found a statistically insignificant incidence of post-contrast AKI and need for dialysis at all levels of baseline kidney function, according to researchers’ poster presentation. At worse, they concluded, the maximum incidence of AKI attributable to CT contrast administration is 1.4%, 5.6%, 11%, and 24% for patients with an estimated glomerular filtration rate above 60, 30-60, 15-30, and less than 15 mL/min/1.73 m2, respectively.
“The benefits of enhanced CT may outweigh this small risk [of CIN] in certain patients with renal dysfunction,” the researchers wrote.
The authors noted that AKI in hospitalized patients is common, which likely leads to inflated reports of the true incidence of CIN associated with contrast CT.