Magnetic resonance imaging (MRI) can safely be used in heart catheter procedures, offering a radiation-free alternative to certain X-ray-guided procedures, according to the U.S. National Institutes of Health in a study from the NIH's National Heart, Lung, and Blood Institute published in the European Heart Journal.
The researchers performed transfemoral catheterization--guiding a catheter from the large vein in the leg to the heart--on 16 patients using both X-ray, the current standard, and MRI as a real-time guide. The MRI procedure was performed twice on 15 patients--once with a balloon-tipped catheter filled with air or with a contrast agent. One patient required a metal guidewire to be used with X-ray, while no guidewires are available that work under an MRI. All the procedures took about the same amount of time, according to a summary.
The researchers had expected the MRI procedures to take longer because the conventional steel catheter is more visible on X-ray than a catheter compatible with MRI.
"Developing safe and conspicuous catheter devices for MRI is the chief obstacle to overcome before this approach can be widely applied at hospitals. ," study lead Robert J. Lederman, M.D., a senior investigator in the NHLBI's Cardiovascular and Pulmonary Branch, said in an announcement. "But with improved tools and further improvement of the procedure, real-time MRI catheterization may become a realistic option for many people."
He cited pediatrics as one area where such a procedure would be especially welcomed. Though the industry as a whole has been trying to reduce patients' exposure to radiation, research linking repeated imaging in childhood to a slightly greater risk later of leukemia and brain cancer has only increased calls to shield children as much as possible from radiation.
The research team is still performing MRI catheterization procedures, working to design tools that will be more visible under MRI.
Two California hospitals recently won legislative approval to perform heart catheterization in outpatient buildings adjacent to their main facilities. Cedars-Sinai Medical Center in Los Angeles and Scripps Memorial Hospital in La Jolla sought the approval as a way to reduce wait times for the procedure, the Los Angeles Times reported. The California Nurses Association had opposed the move, saying it could endanger patients if something went wrong.
Meanwhile, researchers at Johns Hopkins report that an augmented reality overlay system used with MRI can accurately guide a needle for joint arthrography, the injection of contrast material to determine ligament and cartilage injury.