Point of care MRI feasible for stroke detection

The use of a portable, low-field magnetic resonance imaging (MRI) system is safe and viable for the bedside diagnosis of stroke, according to a new study presented at the recently concluded International Stroke Conference of the American Stroke Association (ISC 2020).

“We started this research several years ago because obtaining accessible, meaningful brain imaging for patients has been a major worldwide health care gap for decades,” Kevin Sheth, MD, senior author and chief physician, Division of Neurocritical Care and Emergency Neurology at Yale School of Medicine and Yale New Haven Hospital in Connecticut, said in a press statement. “The whole thing works because we are using low-field magnets to acquire brain images after a stroke.”

Researchers enrolled 85 stroke patients (aged 18–96 years; 46 percent female), in whom point of care MRI was applied. The median National Institutes of Health Stroke Scale (NIHSS) score was 7, with values ranging from 1–29; body mass index values ranged from 20.0–46.5 kg/m². Scans were obtained within 7 days of symptom onset. [ISC 2020, abstract 57]

Eighty-seven percent (n=74) of the participants were able to complete the bedside test, with a mean exam time of 28.9±8.4 minutes, suggesting good intervention feasibility.

Notably, even if no caution was taken to remove traces of and equipment with ferrous material in the room, no evidence of interference with the static field, gradient and radiofrequency pulses of the bedside machine were detected. There were also no reports of significant adverse events due to the scanning.

For the remaining 11 patients, the point of care MRI technology was unsuitable. Five of these participants (6 percent overall) were too big for the machine and were unable to fit through the scanner’s 30-cm opening. The six other patients (7 percent overall) opted to terminate the exam early, complaining of claustrophobia.

In the present study, the point of care scans were performed in Yale’s Neuroscience Intensive Care Unit. The bedside machine was powered by a standard 110-V, 15-A power outlet. The room environment included other equipment, such as vitals monitor, ventilators and intravenous infusion pumps; these were left as they were, testing the ability of the bedside MRI to function in a typical setting.

“We’ve flipped the concept from having to get patients to the MRI to bringing the MRI to the patients,” said Sheth. “This early work suggests our approach is safe and viable in a complex clinical care environment.”

“There’s a lot of work to do. However, we’ve cracked the door open for bringing this technology to any setting, anywhere. In rural settings, urban advanced hospitals and in remote villages in areas of the world where it’s hard to get an MRI – not anymore,” he added.