MR T2WI demonstration of sciatic nerve injury in rabbits / 中国医学影像技术

ABSTRACT

Objective To investigate the relationship between MRI signal,pathological changes and neurological function after sciatic nerve injury in rabbits.Methods Twenty New Zealand white rabbits were randomly and evenly divided into 5 groups,and the right sciatic nerve crush models were established.T2 fat suppression fast recovery spin echo (T2 fs FRFSE) sequence scanning was performed 3 days,7 days,2 weeks,3 weeks and 4 weeks after injury,and TE was set as 30,60 and 90 ms,respectively.Signal intensity ratio (SIR) and relative signal intensity (△S) of proximal and distal part of injured nerve and control side nerve were measured.The relationship between SIR,△S,pathology and rabbit lower limb nerve function were analyzed.Results In the distal part of injured nerve,SIR and △S increased 3-7 days after injury,pathological results showed vacuolar degeneration,and basic toe function lost was found.SIR and △S reached the peak 2 weeks after injury,with most serious disintegration of myelin and toe function disable.SIR,△S and toe function disable gradually recovered,and the nerve regenerated at 3-4 weeks after injury.The injure display rate of T2 fs FRFSE images with TE=90 and 60 ms,SIR of both distal and proximal part of injured nerve were higher than those on images with TE=30 ms (all P＜0.05).Conclusion SIR and △S changes on T2 fs FRFSE imaging can be used to predict rabbit nerve injury.