Diabetic Patients Benefit from Non-contrast MRI
During the past two decades, there has been a dramatic increase in obesity among U.S. residents, according to the Centers for Disease Control and Prevention; in 30 states, more than a quarter of the population is obese (see figure above). The rise in obesity has led, in turn, to an increase in the incidence of diabetes, presenting the radiology community with a fresh challenge: How can radiologists accurately and safely image patients with comorbidities ranging from slow blood flow to kidney disease?
“Vascular disease is obviously a huge problem in the diabetic population and is a major cause of morbidity and mortality, with limb loss and gangrene,” according to Timothy Albert, MD, medical director of the Cardiovascular Diagnostic Center of Salinas Valley Memorial Healthcare System, Monterey, Calif. “At a minimum, it prevents patients from being active, so one of the things we try to emphasize in our community is the importance of aggressively working up this disease. If you can diagnose it, you can treat some patients with cholesterol medications, blood-pressure medications, and so on. For those who have a blockage, you can fix it.”
In 2008, Salinas Valley installed a Vantage™ Atlas MRI system from Toshiba America Medical Systems, Inc. in Tustin, Calif., and began using the scanner’s non-contrast protocol to image more than 90 percent of its patients. “We prefer to image these patients without contrast for a couple of reasons,” Albert notes. “A lot of times, these diabetic patients have some early kidney disease (if not advanced kidney disease), and you’ve got issues with veins not getting enough contrast, especially in the lower extremities.”
The 1.5T Atlas uses Toshiba’s proprietary contrast-free imaging techniques. “In terms of image quality in the renal area, I’d say it’s one-to-one with contrast-enhanced MRI. It’s as good, if not even better; there’s often some improvement, in that you can actually see the branching vessels better than when you’re using contrast, which can wash the image out,” Albert says.
Using non-contrast MRI, however, eliminates other timing issues, such as the need to take the scan while the contrast is flowing through the vessels at an optimal level. “Up to 5 percent of the time, even with an experienced technologist, you can miss it,” he says, “and you’ll still have problems with the veins getting enough contrast.”
Use of the non-contrast technique improves workflow and throughput, Albert says, by eliminating the obstacles that come in tandem with using gadolinium or other contrast agents. “With contrast-enhanced imaging, there’s always a certain percentage of patients whose exams you may need to redo,” he notes. “IV issues themselves—plus the risk of reactions or complications from the IV (although low)—also contribute to the amount of time it can take to scan one patient.”
There are throughput benefits specific to imaging the bariatric/diabetic population, he adds. “With diabetic patients, it can be hard to find a vein, and sometimes you can’t get an IV the size you need for a rapid injection. You can spend 20 minutes looking for the right size IV,” Albert says. “For patients with kidney disease, logistically, it’s nice not to have to make sure you’ve got their latest kidney-function tests, because that can slow the process of getting patients through, and for patients who do have a contraindication for gadolinium, we’re not dusting off the books and trying something new. This is what we do routinely.”
Non-contrast MRI also saves money—well over $100 per study, according to Albert. “We’re in a day and age when reimbursement is getting cut and cut, and this is a big way to save,” he says. “It’s not only the contrast bill, which could be up to $100 for the average study. You’ve also got IV supplies, and nursing time to put in the IV. We’re working on some financial models to compare the two, but you’re probably looking at saving up to $150 per study.”
Albert emphasizes that while the non-contrast technique is particularly beneficial in imaging the diabetic population, it can be used on any patient. “There are a lot of misconceptions out there regarding who is the ideal patient for this,” he says. “We’ve done a cross-section of patients of every size in the past year, and we’ve had very good results. This really is a robust technique.”
Tags: MRI, Non-Contrast
Category: Medical Imaging —