Dynamic contrast-enhanced magnetic resonance imaging in denervated skeletal muscle: Experimental study in rabbits.

Liang Qi,Yue-Fen Zou,Lei Xu,Rui Zhang,Hai-Bin Shi,Wen-Tao Wang,Yu-Dong Zhang,Xi Chen

doi:10.1371/journal.pone.0215069

Liang Qi, Yue-Fen Zou + Show 6 more

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https://doi.org/10.1371/journal.pone.0215069

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Abstract

PurposeTo investigate the value of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for evaluating denervated skeletal muscle in rabbits.Materials and methods24 male rabbits were randomly divided into an irreversible neurotmesis group and a control group. In the experimental group, the sciatic nerves of rabbits were transected for irreversible neurotmesis model. A sham operation was performed in the control group. MRI of rabbit lower legs was performed before nerve surgery and 1 day, 3 days, 5 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, and 12 weeks after surgery.ResultsSignal intensity changes were seen in the left gastrocnemius muscle on the T2-weighted images. DCE-MRI derived parameters (Ktrans, Kep, and Vp) were measured in vivo. In the irreversible neurotmesis group, T2-weighted images showed increased signal intensity in the left gastrocnemius muscle. Ktrans, Vp values changes occur as early as 1 day after denervation, and increased gradually until 4 weeks after surgery. There are significant increases in both Ktrans and Vp values compared with those in the control group after surgery (P < 0.05). Kep values show no significant difference between the irreversible neurotmesis group and the control group.ConclusionDCE-MRI hold the promise of an early and sensitive diagnosis of denervated skeletal muscle.

Highlights

Peripheral nerve injury leads to morphologic and metabolic changes in the target denervated skeletal muscles
Signal intensity changes were seen in the left gastrocnemius muscle on the T2-weighted images
Vp values changes occur as early as 1 day after denervation, and increased gradually until 4 weeks after surgery

Summary

Introduction

Peripheral nerve injury leads to morphologic and metabolic changes in the target denervated skeletal muscles. Electromyography (EMG) is useful for the diagnosis of denervated muscles [1]. EMG sometimes presents some difficulties in the detection of denervated skeletal muscle because it is both invasive and dependent on the skill of the examiner, and it is difficult to obtain information that is useful, objective, and reproducible with EMG in the deep muscles or small intramuscular areas. Conventional magnetic resonance imaging (MRI) has proved to be useful in the diagnosis of denervated skeletal muscle after peripheral nerve injury [2,3,4,5]. Denervated skeletal muscle usually show high signal intensity on T2-weighted MR images and normal signal intensity on T1-weighted MR images. Numerous previous articles have corroborated these findings [2, 3, 5,6,7,8]

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