Quantitative MRI Differentiates Electromyography Severity Grades of Denervated Muscle in Neuropathy of the Brachial Plexus.
J Magn Reson Imaging
; 56(4): 1104-1115, 2022 Oct.
Article
in En
| MEDLINE
| ID: mdl-35195321
ABSTRACT
BACKGROUND:
Quantitative MRI (qMRI) metrics reflect microstructural skeletal muscle changes secondary to denervation and may correspond to conventional electromyography (EMG) assessments of motor unit recruitment (MUR) and denervation.HYPOTHESIS:
Differences in quantitative T2 , diffusion-based apparent fiber diameter (AFD), and fat fraction (FF) exist between EMG grades, in patients with clinically suspected neuropathy of the brachial plexus. STUDY TYPE Prospective. POPULATION A total of 30 subjects (age = 37.5 ± 17.5, 21M/9F) with suspected brachial plexopathy. FIELD STRENGTH/SEQUENCE 3-Tesla; qMRI using fast spin echo (T2 -mapping), multi-b-valued diffusion-weighted echo planar imaging (for AFD), and dual-echo Dixon gradient echo (FF-mapping) sequences. ASSESSMENT qMRI values were compared against EMG grades (MUR and denervation). qMRI values (T2 , AFD, and FF) were obtained for five regional shoulder muscles. A 4-point scale was used for MUR/denervation severity. STATISTICAL TESTS Linear mixed models and least-squares pairwise comparisons were used to evaluate qMRI differences between EMG grades. Predictive accuracy of EMG grades from qMRI was quantified by 10-fold cross-validated logistic models. A P value < 0.05 was considered statistically significant.RESULTS:
Mean (95% confidence interval) qMRI for "full" MUR were T2 = 39.40 msec (35.72-43.08 msec), AFD = 78.35 µm (72.52-84.19 µm), and FF = 4.54% (2.11-6.97%). Significant T2 increases (+8.36 to +14.67 msec) and significant AFD decreases (-11.04 to -21.58 µm) were observed with all abnormal MUR grades as compared to "full" MUR. Significant changes in both T2 and AFD were observed with increased denervation (+9.59 to +15.04 msec, -16.25 to -18.66 µm). There were significant differences in FF between some MUR grades (-1.45 to +2.96%), but no significant changes were observed with denervation (P = 0.089-0.662). qMRI prediction of abnormal MUR or denervation was strong (mean accuracy = 0.841 and 0.810, respectively) but moderate at predicting individual grades (accuracy = 0.492 and 0.508, respectively). DATACONCLUSION:
Quantitative T2 and AFD differences were observed between EMG grades in assessing muscle denervation. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY Stage 1.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Brachial Plexus
/
Magnetic Resonance Imaging
Type of study:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Humans
Language:
En
Journal:
J Magn Reson Imaging
Journal subject:
DIAGNOSTICO POR IMAGEM
Year:
2022
Document type:
Article
Affiliation country:
United States