IV Contrast-Enhanced CT Safe for Most Patients

September 10, 2014

Intravenous contrast material for CT appears to be safe for most patients, including those with a predisposition to nephrotoxicity.

Use of IV contrast material was not associated with excess risk of acute kidney injury (AKI), dialysis or death, according to a study published in the journal Radiology.

Researchers from the Mayo Clinic in Rochester, Minn., and Medical University of South Carolina, Charleston, performed a single-center retrospective study to determine the risk of emergent dialysis and short-term mortality following IV iodinated contrast material exposure.

“For nearly 60 years, physicians have worried about contrast-induced nephropathy when using iodinated contrast material, particularly for patients with impaired kidney function,” researcher Robert J. McDonald, MD, PhD, radiology resident, Mayo Clinic, said in a release. “Emerging evidence now suggests these concerns are likely vastly overestimated.”[[{"type":"media","view_mode":"media_crop","fid":"27652","attributes":{"alt":"Study flowchart. Image courtesy of Radiology. © RSNA, 2014","class":"media-image media-image-right","id":"media_crop_883133206942","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"2720","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"height: 597px; width: 225px; border-width: 0px; border-style: solid; margin: 1px; float: right;","title":" Study flowchart. Image courtesy of Radiology. © RSNA, 2014","typeof":"foaf:Image"}}]]

The researchers identified all contrast material–enhanced (contrast group) and unenhanced (noncontrast group) abdominal, pelvic and thoracic computed tomography scans from 2000 to 2010. A total of 21,346 patients were included in the study: 10,673 patients who each underwent a contrast-enhanced CT exam and 10,673 patients who underwent a similar CT without intravenous contrast. The two groups were closely matched by demographic and clinical characteristics.

Patients with preexisting conditions such as diabetes, congestive heart failure or chronic or acute renal failure were identified as high-risk patient subgroups for nephrotoxicity. The researchers looked at adverse events following the CT scans, including acute kidney injury, the need for emergency renal dialysis (in patients with no prior history of dialysis) and death within 30 days of contrast exposure.

The results showed no significant differences between the two groups. It was found that patients who developed AKI had higher rates of dialysis and mortality, but contrast material exposure was not an independent risk factor for either outcome for dialysis or for mortality, even among patients considered to be at high risk.

“These results challenge long-held assumptions regarding the presumed nephrotoxic risk of intravenous contrast material,” McDonald said. “We hope that our findings will help refine the safety profile of these contrast agents."