Portable MRI makes bedside brain injury assessment possible for critically ill patients

A prospective, single-centre cohort study in 50 patients demonstrates the feasibility of bedside neuroimaging with low-magnetic field portable MRI in intensive care settings and reports a 40 percent prevalence of neuronal abnormalities among patients with coronavirus disease 2019 (COVID-19).

“To ensure patient safety in and around high-field scanners, the traditional neuroimaging workflow requires patient transport to dedicated hospital imaging suites, which renders MRI largely inaccessible in the setting of critical illness,” wrote the researchers. [Radiology 2011;258:889-905; Eur J Trauma Emerg Surg 2010;36:346-352; J Neurosci Nurs 2010;42:109-116; JAMA 2010;304:208-209]  “In this report, we demonstrate the role of a novel bedside neuroimaging solution, which we recently developed, in neuroscience intensive care units [ICUs] and COVID-19 ICUs.” [JAMA Neurol 2020, doi: 10.1001/jamaneurol.2020.3263]

The new point-of-care (POC) MRI device uses no cryogens and can be plugged into a single, 110 V, 15 A standard power outlet. “The device dimensions render it maneuverable within the confines of an ICU patient room,” noted the researchers. “A self-contained motor and driving capability facilitate the deployment of a single device across the institution.”

The study included patients (women, 32 percent; mean age, 59 years) who presented with ischaemic stroke (n=9), haemorrhagic stroke (n=12), subarachnoid haemorrhage (n=2), traumatic brain injury (n=3), brain tumour (n=4), or COVID-19 with altered mental status (n=20). Neuroimaging findings were detected in 29 of 30 patients who did not have COVID-19 (97 percent). “All POC MRI findings were in agreement with available conventional radiology reports, except for one patient who had diffuse subarachnoid haemorrhage that was not observed on POC MRI [κ=0.65; p<0.001],” reported the researchers.

Among 20 patients with COVID-19, neuroimaging findings were observed in eight patients (40 percent), and included intracranial haemorrhage (n=1), cerebral infarction (n=3), diffuse cerebral oedema (n=1), and leukoencephalopathy (n=3). “Of the 11 patients [55 percent] who received conventional neuroimaging [CT, n=8; MRI, n=3], all POC MRI findings were in agreement with conventional radiology reports,” wrote the researchers.

There were no adverse events or complications associated with POC MRI in any of the study patients.

“In acute neurological settings, it is well established that noninvasive, time-sensitive neuroimaging is the cornerstone of triage and treatment pathways. For ICUs, access to MRI is limited, and the risks of transporting patients with critical illness are well documented. Risks to inpatient populations and clinicians are potentially increased when considering infection control issues, as illustrated by the COVID-19 pandemic,” wrote the researchers. “Recent advances in low-magnetic field MRI have made it possible to safely deploy an MRI scanner into a complex and restricted bedside clinical environment.”