Open AccessAssociations between apparent diffusion coefficient and electromyography parameters in myositis—A preliminary study
Author(s) -
Meyer HansJonas,
Emmer Alexander,
Kornhuber Malte,
Surov Alexey
Publication year - 2018
Publication title -
brain and behavior
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 41
ISSN - 2162-3279
DOI - 10.1002/brb3.958
Subject(s) - effective diffusion coefficient , electromyography , medicine , myositis , nuclear medicine , diffusion mri , pathological , histopathology , magnetic resonance imaging , radiology , pathology , physical medicine and rehabilitation
Objective MRI is widely used in several muscle disorders. Diffusion‐weighted imaging ( DWI ) is an emergent imaging modality sensitive to microstructural alterations in tissue. The apparent diffusion coefficient ( ADC ) is used to quantify the random motion of water molecules. Electromyography ( EMG ) is a clinically used diagnostic tool in myositis. The aim of this study was to elucidate possible associations between ADC values and EMG findings in myositis patients. Method Seven patients (eight investigated muscles) with myositis (mean age 51.43 ± 19 years) were included in this study. The diagnosis was confirmed by histopathology in every case. DWI was obtained with a 1.5‐T scanner using two b‐values 0 and 1000 s/mm². In all patients, a needle electromyography ( EMG ) was performed within 3 days to the MRI . The following EMG parameters were studied: motor unit action potential ( MUAP ) amplitudes and durations, as well as pathological spontaneous activity. Spearman's correlation coefficient was used to analyze associations between investigated parameters. Results The estimated mean ADC mean value was 1.51 ± 0.29 × 10 −3 mm²/s, mean ADC min was 1.28 ± 0.27 × 10 −3 mm²/s, and mean ADC max was 1.73 ± 0.28 × 10 −3 mm²/s. Correlation analysis identified significant associations between ADC mean and duration of the MUAP (p = .78 P = .0279) and between ADC min and duration of the MUAP (p = .85, P = .01). There were no significant differences according to pathological spontaneous activity. Conclusion ADC mean and ADC min showed strong positive correlations with the duration of the MUAP in myositis patients. Both modalities might similarly reflect muscle fiber loss in myositis patients.