Line scan diffusion spectrum of the denervated rat skeletal muscle.
OBJECTIVE
To detect the earlier changes of the skeletal muscle of rats after peripheral nerve injury by measuring the apparent diffusion coefficient (ADC) on diffusion MR spectroscopy.


METHODS
The posterior tibial nerve was transected in six rats (nerve transection group) and was only dissected in six rats (control group). At one, three, five, seven, 14, and 28 days after the surgery, both the T2 value and the ADC of gastrocnemius muscle were measured using a line-scan diffusion spectrum on a 1.5T clinical MR imager on both groups.


RESULTS
In the nerve transection group, the T2 ratio compared to the contralateral side increased gradually over four weeks after the transection, while the ADC ratio increased right after the surgery and began to decrease at five days. Four weeks after the transection, the ADC ratio returned to normal while the T2 ratio stayed at a high value. The control group indicated an almost constant T2 and ADC ratio during the experimental periods.


CONCLUSIONS
The ADC of the skeletal muscle increased quickly after the transection of the dominant peripheral nerve and was detectable one day after the surgery. Diffusion MRI can be a useful tool for early detection of peripheral nerve injury instead of T2-weighted MRI or electromyography (EMG).
Yamabe
Eiko
E
Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
Nakamura
Toshiyasu
T
Oshio
Koichi
K
Kikuchi
Yoshito
Y
Toyama
Yoshiaki
Y
Ikegami
Hiroyasu
H
D000704:Analysis of Variance; D000818:Animals; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D009121:Muscle Denervation; D018482:Muscle, Skeletal / Q000294:innervation*; D051381:Rats; D017208:Rats, Wistar; D013979:Tibial Nerve / Q000601:surgery