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

PURPOSE: To investigate the value of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for evaluating denervated skeletal muscle in rabbits. MATERIALS AND METHODS: 24 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. RESULTS: Signal intensity changes were seen in the left gastrocnemius muscle on the T2-weighted images. DCE-MRI derived parameters (K(trans), K(ep), and V(p)) were measured in vivo. In the irreversible neurotmesis group, T2-weighted images showed increased signal intensity in the left gastrocnemius muscle. K(trans), V(p) values changes occur as early as 1 day after denervation, and increased gradually until 4 weeks after surgery. There are significant increases in both K(trans) and V(p) values compared with those in the control group after surgery (P < 0.05). K(ep) values show no significant difference between the irreversible neurotmesis group and the control group. CONCLUSION: DCE-MRI hold the promise of an early and sensitive diagnosis of denervated skeletal muscle.