The FDA is investigating CT brain perfusion studies for diagnosing and treating stroke, according an October 8 notice on the agency Web site. The concern rose out of 206 patients at one facility in an 18-month period who received radiation doses that were approximately eight times the expected level. The patients were supposed to receive a maximum dose of 0.5 Gy but instead received received 3 Gy to 4 Gy doses, according to the FDA.

The American College of Radiology reported that the FDA is concerned that the situation at this incident may “reflect more widespread problems with CT quality assurance programs” and that FDA encourages facilities to review their CT protocols and to “report any medical device adverse events related to CT that do not meet the requirements for mandatory reporting.”

A new study in the Clinical Journal of the American Society of Nephrology reported that what was thought to be minor, reversible contrast-induced nephropathy actually increases patient’s long-term risk of stroke, renal faillure and other complications.

While prospective studies are needed to prove causality, the trial examined nephropathy associated with two contrast agents, iodixanol (Visipaque) and iopamidol (Isovue). Richard J. Solomon, MD, of the University of Vermont in Burlington, and colleagues conducted the retrospective review, which found a two- to four-times higher rate of adverse events among patients receiving iodixanol.

Below is a MedPageToday interview with Solomon discussing the research.