CT procedures has proven riskier than MRI when it comes to accidental contrast medium extravasation (CME), a recent study finds.

Led by Khalid Shaqdan, MD, of Massachusetts General Hospital, the study was published Sept. 22 in Clinical Radiology. 

CME is a common complication in these procedures and while the injuries related to CME are usually minor and resolve on their own, some occurrences result in more serious complications that lead to extended hospital stays, increased morbidity and higher costs.

Advancing CT technology has allowed for multiphasic organ imaging and quicker delivery of intravenous contrast media, and faster mechanical injection rates allow for optimal image enhancement, which increases the likelihood of detecting disease.

Shagdan and colleagues noted certain risk factors have been shown to increase the chances a patient develops CME, including choice of injection site, patients unable to communicate with medical staff and even arterial insufficiency.

The research team studied CT and MRI examinations that included contrast media injections between June 2008 and June 2013—a total of 502,391 procedures. Adverse effects experienced by patients related to contrast material were identified by a query of the institutional electronic safety reporting system.

Results of the retrospective research showed 451 CT procedure CME events (0.13 percent) occurred during the study period—254 patients were female and 197 were male, both with a mean age of 60. For the MRI procedures, 90 resulted in CME events (0.06 percent)—57 women and 33 men, with a mean age of 58 years.

Of the 541 patients with CME, 43 felt no adverse effects from the CME, 497 had MTH (symptoms included pain and swelling) and one adult had injuries that included blistering or ulceration of the skin. None of the CME patients needed surgical procedures, though two were referred for further surgical consult. These two patients had large extravasation volumes (approximately 100 ml).

“When comparing the incidence of CME at CT to MRI, patients undergoing CT contrast-enhanced studies were at a higher risk of developing extravasation,” the study authors noted, though previous studies cited in the research noted the risk of CME is greater during CT than MRI due to the volume and rapidity of contrast material being administered.

Shagdan and colleagues noted that females and inpatients were at a higher risk of CME for both CT and MRI procedures. Additionally, patient age played a factor in CME risk—patients above the age of 60 had the highest CME rates in both CT and MRI procedures.

“Despite what is already known from the literature, there still remains some discrepancy as to what is the exact cause for the higher risks in certain groups of patients,” the authors wrote.  “Further studies are needed not only discover the reasons for those discrepancies, but also ways to decrease them.”