Magnetic Resonance Neurography and Diffusion Tensor Imaging of the peripheral nerves in patients with CMT Type 1A

INTRODUCTION: Investigation of peripheral neuropathies by magnetic resonance neurography (MRN) may provide increased diagnostic accuracy when performed in combination with diffusion tensor imaging (DTI). The aim of this study was to evaluate DTI in the detection of neuropathic abnormalities in Charcot-Marie-Tooth-type-1A (CMT1A).

METHODS: MR imaging of the sciatic and tibial nerves, including MRN and DTI, was prospectively performed in 15 CMT1A patients and 30 healthy-controls (HC). The following MRI parameters were evaluated and correlated with clinical and neurophysiological findings: T2-relaxation-time(T2), proton-spin-density(PD) and DTI (fractional-anisotropy(FA) and apparent-diffusion-coefficient(ADC)).

RESULTS: DTI showed lower FA and higher ADC in CMT1A as compared to HC. T2 showed no difference, however, PD of the sciatic nerve was higher in CMT1A. There were some close associations between neuropathy severity and MRN-DTI, with the closest correlation between FA and nerve-conduction-velocity in the sciatic nerve (r=0.76;p<0.01).

DISCUSSION: MRN-DTI evaluation of sciatic and tibial nerves improves the detection of nerve abnormalities in patients with CMT1A. This article is protected by copyright. All rights reserved.