Future of Neurology & Technology: Neuroimaging Made Accessible Using Low-Field, Portable MRI

Abstract

In the 20^th century, the advent of neuroimaging dramatically altered the field of neurological care. However, despite iterative advances since the invention of Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI), little progress has been made to bring MR neuroimaging to the point-of-care. Recently, the emergence of a low-field (LF) (<1 Tesla (T)), portable MRI (pMRI) is setting the stage to revolutionize the landscape of accessible neuroimaging. Users can transport the pMRI into a variety of locations, using a standard 110-220V wall outlet. In this article, we discuss current applications for pMRI including in the acute and critical care settings, as well as the barriers to broad implementation, and future opportunities.

Background

In 1971, the development of CT transformed neuroimaging. For the first time, the brain could be visualized noninvasively¹. MRI further revolutionized the field by coupling an external magnetic field with radiofrequency (RF) energy to provide greater soft tissue contrast and more precise anatomic visualization than CT^2,3. However, conventional MRI (cMRI) scanners operate at a high magnetic field strength (1.5-3 T), are costly to purchase ($1M per T), and require expensive infrastructure⁴. Patients must be moved from clinical environments to controlled access remote imaging suites, often causing delays in image acquisition. This transport is associated with cardiovascular and respiratory risks, which are exacerbated by the inability to deploy interventions in transit^{5, 6}. While use of portable CT (pCT) can evade these hazards, it carries the risk of radiation⁷. Thus, the ability to obtain MR neuroimaging at the point-of-care may reshape neurological care (Figure).

For more information on pMRI background, please refer to eAppendix 1, which includes a discussion comparing pMRI versus cMRI and pCT and an explanation of pMRI specifications. eAppendix 1 also involves a clinical case highlighting pMRI’s utility and a description of similar devices.