Objective: This study evaluates the feasibility of diffusion tensor imaging(DTI) in assessing median
nerve by measuring diffusion parameters such as fractional anisotropy (FA), mean diffusivity (MD),
axial diffusivity (AD) and radial diffusivity (RD) at different sites of median nerve and evaluating
their differences in patients with and without carpal tunnel syndrome (CTS) in local setting. Methods:
A prospective cross sectional study was performed with 9 female patients diagnosed with CTS by
clinical evaluation and nerve conduction study and 8 age and sex matched normal patients. Magnetic
resonance imaging (MRI) wrist was performed with pre-set axial PD and DTI protocol on a 3T
MRI, images post-processed using 3D SLICER software to generate median nerve tract and measure
diffusion parameters FA, MD, AD and RD in segments and focal points. Results: The FA values were
significantly lower in CTS patients, 0.454 (± 0.065), p< 0.002 and demonstrates negative correlation
with disease severity, r = - 0.510, p = 0.002.The mean MD, 1.090 (± 0.178) and mean RD, 0.834
(± 0.128) is higher in CTS patients, p = 0.041 and p = 0.014 respectively. They show an increasing
trend with increasing disease severity. Negative correlation was noted between the FA values and
age groups. FA cut of value of ≤ 0.487 with sensitivity 70.6 % and specificity 76.5%, is suggested
for diagnosing CTS.
Conclusion: MR neurography using DTI can be utilised to detect CTS. Patients with CTS demonstrate
lower FA and higher MD and RD values.