Volume 63, Issue 5 pp. 703-709
CLINICAL RESEARCH ARTICLE

Quantitative T2-mapping magnetic resonance imaging for assessment of muscle motor unit recruitment patterns

Erin C. Argentieri BS

Erin C. Argentieri BS

Department of Radiology and Imaging, Hospital for Special Surgery, New York, New York, USA

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Ek Tsoon Tan PhD

Ek Tsoon Tan PhD

Department of Radiology and Imaging, Hospital for Special Surgery, New York, New York, USA

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Jeremy S. Whang MD

Jeremy S. Whang MD

Department of Radiology and Imaging, Hospital for Special Surgery, New York, New York, USA

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Sophie C. Queler BA

Sophie C. Queler BA

Department of Radiology and Imaging, Hospital for Special Surgery, New York, New York, USA

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Joseph H. Feinberg MD

Joseph H. Feinberg MD

Departments of Physiatry and Sports Medicine, Hospital for Special Surgery, New York, New York, USA

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Bin Lin ScM

Bin Lin ScM

Department of Radiology and Imaging, Hospital for Special Surgery, New York, New York, USA

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Darryl B. Sneag MD

Corresponding Author

Darryl B. Sneag MD

Department of Radiology and Imaging, Hospital for Special Surgery, New York, New York, USA

Correspondence

Darryl B. Sneag MD, Department of Radiology and Imaging, Hospital for Special Surgery, Weill Medical College of Cornell University, 535 East 70th Street, New York, NY 10021.

Email: [email protected]

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First published: 26 January 2021
Citations: 12

Funding information: National Center for Advancing Translational Sciences of the National Institutes of Health (NIH), Grant Number: 1R21TR003033-01A1. The contents of this article are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.

Funding information: National Center for Advancing Translational Sciences, Grant/Award Number: NIH R21-TR003033

Abstract

Introduction

In this study, we aimed to determine whether muscle transverse relaxation time (T2) magnetic resonance (MR) mapping results correlate with motor unit loss, as defined by motor unit recruitment patterns on electromyography (EMG).

Methods

EMG and 3-Tesla MRI exams were acquired no more than 31 days apart in subjects referred for peripheral nerve MRI. Two musculoskeletal radiologists qualitatively graded T2-weighted, fat-suppressed sequences for severity of muscle edema-like patterns and manually placed regions of interest within muscles to obtain T2 values from T2-mapping sequences. Concordance was calculated between qualitative and quantitative MR grades and EMG recruitment categories (none, discrete, decreased) as well as interobserver agreement for both MR grades.

Results

Thirty-four muscles (21 abnormal, 13 control) were assessed in 13 subjects (5 females and 8 males; mean age, 46 years) with 14 EMG-MRI pairs. T2-relaxation times were significantly (P < .001) increased in all EMG recruitment categories compared with control muscles. T2 differences were not significant between EMG grades of motor unit recruitment (P = .151-.702). T2 and EMG score concordance was acceptable (Harrellʼs concordance index [c index]: rater A, 0.71; 95% confidence interval [CI], 0.51-0.87; rater B, 0.77; 95% CI, 0.57-0.91). Qualitative MRI and EMG score concordance was poor to acceptable (c index: rater A, 0.60; 95% CI, 0.50-0.79; rater B, 0.72; 95% CI, 0.55-0.89). T2 values had moderate-to-substantial ability to distinguish between absent vs incomplete (ie, decreased or discrete) motor unit recruitment (c index: rater A, 0.78; 95% CI, 0.50-1.00; rater B, 0.86; 95% CI, 0.57-1.00).

Discussion

Quantitative T2 MR muscle mapping is a promising tool for noninvasive evaluation of the degree of motor unit recruitment loss.

CONFLICT OF INTEREST

The authors report an institutional research agreement between Hospital for Special Surgery and General Electric Healthcare.

DATA AVAILABILITY STATEMENT

The anonymized data that support the findings of this study are available from the corresponding author upon reasonable request.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.

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