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Original Investigation
September 8, 2020

Assessment of Brain Injury Using Portable, Low-Field Magnetic Resonance Imaging at the Bedside of Critically Ill Patients

Author Affiliations
  • 1Department of Neurology, Yale University School of Medicine, New Haven, Connecticut
  • 2Neuroscience Intensive Care Unit, Yale New Haven Hospital, New Haven, Connecticut
  • 3Department of Neurosurgery, Yale School of Medicine, New Haven, Connecticut
  • 4Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
  • 5Hyperfine Research Inc, Guilford, Connecticut
  • 6Department of Radiology, Yale University School of Medicine, New Haven, Connecticut
  • 7Division of Pulmonology and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut
  • 8Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown
  • 9Division of Neurology Infections & Global Neurology, Department of Neurology, Yale University School of Medicine, New Haven, Connecticut
  • 10Division of Neurocritical Care, Department of Neurology, Massachusetts General Hospital, Boston
JAMA Neurol. 2021;78(1):41-47. doi:10.1001/jamaneurol.2020.3263
Key Points

Question  Can brain injury in patients who are critically ill be assessed using a novel portable, low-field magnetic resonance imaging (MRI) device at the bedside in an intensive care setting?

Findings  In this cohort study of a series of 50 patients imaged with a portable, bedside MRI device, including patients with ischemic stroke, hemorrhagic stroke, subarachnoid hemorrhage, traumatic brain injury, brain tumor, and COVID-19 and altered mental status, abnormal neuroimaging findings were detected in 29 of 30 patients without COVID-19 (97%); 8 of 20 patients with COVID-19 (40%) demonstrated abnormalities. There were no adverse events or complications.

Meaning  This study demonstrates the capability of low-field, portable MRI to obtain neuroimaging at the bedside in intensive care settings.


Importance  Neuroimaging is a key step in the clinical evaluation of brain injury. Conventional magnetic resonance imaging (MRI) systems operate at high-strength magnetic fields (1.5-3 T) that require strict, access-controlled environments. Limited access to timely neuroimaging remains a key structural barrier to effectively monitor the occurrence and progression of neurological injury in intensive care settings. Recent advances in low-field MRI technology have allowed for the acquisition of clinically meaningful imaging outside of radiology suites and in the presence of ferromagnetic materials at the bedside.

Objective  To perform an assessment of brain injury in critically ill patients in intensive care unit settings, using a portable, low-field MRI device at the bedside.

Design, Setting, and Participants  This was a prospective, single-center cohort study of 50 patients admitted to the neuroscience or coronavirus disease 2019 (COVID-19) intensive care units at Yale New Haven Hospital in New Haven, Connecticut, from October 30, 2019, to May 20, 2020. Patients were eligible if they presented with neurological injury or alteration, no contraindications for conventional MRI, and a body habitus not exceeding the scanner’s 30-cm vertical opening. Diagnosis of COVID-19 was determined by positive severe acute respiratory syndrome coronavirus 2 polymerase chain reaction nasopharyngeal swab result.

Exposures  Portable MRI in an intensive care unit room.

Main Outcomes and Measures  Demographic, clinical, radiological, and treatment data were collected and analyzed. Brain imaging findings are described.

Results  Point-of-care MRI examinations were performed on 50 patients (16 women [32%]; mean [SD] age, 59 [12] years [range, 20-89 years]). Patients presented with ischemic stroke (n = 9), hemorrhagic stroke (n = 12), subarachnoid hemorrhage (n = 2), traumatic brain injury (n = 3), brain tumor (n = 4), and COVID-19 with altered mental status (n = 20). Examinations were acquired at a median of 5 (range, 0-37) days after intensive care unit admission. Diagnostic-grade T1-weighted, T2-weighted, T2 fluid-attenuated inversion recovery, and diffusion-weighted imaging sequences were obtained for 37, 48, 45, and 32 patients, respectively. Neuroimaging findings were detected in 29 of 30 patients who did not have COVID-19 (97%), and 8 of 20 patients with COVID-19 (40%) demonstrated abnormalities. There were no adverse events or complications during deployment of the portable MRI or scanning in an intensive care unit room.

Conclusions and Relevance  This single-center series of patients with critical illness in an intensive care setting demonstrated the feasibility of low-field, portable MRI. These findings demonstrate the potential role of portable MRI to obtain neuroimaging in complex clinical care settings.

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