Portable, bedside, low-field magnetic resonance imaging for evaluation of intracerebral hemorrhage

Mercy H Mazurek ,Gordon Sze ,Kevin T Gobeske ,Audrey C Leasure ,Jill Shah ,Joseph Schindler ,Teng J Peng ,Anjali M Prabhat ,Isha R Chavva ,Jonathan M Rothberg ,Laura Sacolick ,Matthew Ming Fai Yuen ,Jens Witsch ,Michael Poole ,Matthew S Rosen ,Joseph Antonios ,Lauren Sansing ,Charles Wira ,Bradley A Cahn ,Charles Matouk ,Nils Petersen ,Adrienne Ward ,Rachel Beekman ,W Taylor Kimberly ,Anna Crawford ,Emily J Gilmore ,Nona Timario ,David Y Hwang ,E Brian Welch ,Jennifer A Kim ,Guido J Falcone ,Kevin N Sheth

doi:10.1038/s41467-021-25441-6

Abstract

Radiological examination of the brain is a critical determinant of stroke care pathways. Accessible neuroimaging is essential to detect the presence of intracerebral hemorrhage (ICH). Conventional magnetic resonance imaging (MRI) operates at high magnetic field strength (1.5–3 T), which requires an access-controlled environment, rendering MRI often inaccessible. We demonstrate the use of a low-field MRI (0.064 T) for ICH evaluation. Patients were imaged using conventional neuroimaging (non-contrast computerized tomography (CT) or 1.5/3 T MRI) and portable MRI (pMRI) at Yale New Haven Hospital from July 2018 to November 2020. Two board-certified neuroradiologists evaluated a total of 144 pMRI examinations (56 ICH, 48 acute ischemic stroke, 40 healthy controls) and one ICH imaging core lab researcher reviewed the cases of disagreement. Raters correctly detected ICH in 45 of 56 cases (80.4% sensitivity, 95%CI: [0.68–0.90]). Blood-negative cases were correctly identified in 85 of 88 cases (96.6% specificity, 95%CI: [0.90–0.99]). Manually segmented hematoma volumes and ABC/2 estimated volumes on pMRI correlate with conventional imaging volumes (ICC = 0.955, p = 1.69e-30 and ICC = 0.875, p = 1.66e-8, respectively). Hematoma volumes measured on pMRI correlate with NIH stroke scale (NIHSS) and clinical outcome (mRS) at discharge for manual and ABC/2 volumes. Low-field pMRI may be useful in bringing advanced MRI technology to resource-limited settings.

Highlights

Radiological examination of the brain is a critical determinant of stroke care pathways
We obtained 119 portable MRI (pMRI) examinations on 104 patients presenting to the neuroscience intensive care unit (NICU) or emergency department (ED) with a confirmed diagnosis of intracerebral hemorrhage (ICH) or acute ischemic stroke (AIS)
5 pMRI examinations reached the level of the midbrain (4%), 25 exams reached the level of the pons (17%), 107 exams reached the level of the medulla (74%), and 7 exams reached the level of the lateral ventricles (5%)

Summary

Introduction

Radiological examination of the brain is a critical determinant of stroke care pathways. Accessible neuroimaging is essential to detect the presence of intracerebral hemorrhage (ICH). Since intracerebral hemorrhage (ICH) is a contraindication for thrombolytic therapy[3,4], ruling out the presence of blood is one of the main decision steps in acute stroke care. A growing body of recent evidence has demonstrated that multimodal magnetic resonance imaging (MRI) is as accurate as CT for detecting acute brain hemorrhage[9,10,11,12,13,14,15,16,17,18] and avoids the radiation exposure associated with CT19. In addition to acute stroke evaluation, other clinical contexts, such as post-neurosurgical assessment of patients, require neuroimaging evaluation to detect the presence of ICH. Clinicians commonly use ICH volume as a critical determinant of prognostication[26]

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