Portable MRI shows promise in detecting infarcts for those with acute ischemic stroke

Key takeaways:

• The portable MRI detected a high percentage of stroke-related infarct.
• Hyperfine has “practical advantages” over high-field MRI, researchers said.

Portable bedside MRI showed promise in detecting infarcts revealed on high-field MRI in those with acute ischemic stroke, with better performance on larger sized infarcts, according to a poster from the International Stroke Conference.

“FDA approval of Hyperfine has led to interest in using low-field MRI in acute ischemic stroke,” James Shay, MD, a behavioral neurology fellow at Ohio State University Wexner Medical Center, and colleagues wrote. “Portable MRI has practical advantages over high-field MRI and prior studies have evaluated pMRI predominantly in the ICU settings.”

Researchers aimed to determine performance of Hyperfine, an FDA-approved, portable, bedside MRI, on patients with floor-level acute ischemic stroke.

Their study was a retrospective review of 12 individuals (mean age 58.5 years; 58.3% female) who had undergone pMRI during their hospitalization.

Shay and fellow researchers reviewed their institutional pMRI (Hyperfine), an 0.064 Tesla that includes diffusion-weighted imaging (DWI), to visually confirm infarcts on high-field MRI (hMRI). The hMRI is considered “gold standard,” the researchers wrote, excluding all incomplete or technically limited scans. Infarct size was measured based upon maximum longitudinal axis on MRI DWI.

According to results, the mean time from hMRI to pMRI was 46.2 hours (range, -0.9 to 126.9 hours).

In nine of 12 patients, pMRI revealed acute infarcts (seven of 12 pMRI scans demonstrated all infarcts seen on hMRI, while two of 12 pMRI scans identified some but not all), while three pMRI DWI were negative and 12 hMRI scans revealed a total of 15 infarct lesions.

Among those 15, 10 were also visible on pMRI, with mean size of non-visible infarcts 7.7 mm, compared with pMRI visible infarct mean size of 21.7mm. The smallest infarct that was visible on the pMRI was 7.7 mm.

“Understanding limitations of pMRI will allow clinical teams to maximize patient selection for use in [acute ischemic stroke] population,” Shay and colleagues wrote.