Lucas Gama Lobo MD, Presenter: Nothing to Disclose

Lawrence M. White MD, Abstract Co-Author: Advisory Board, Siemens AG

Monica Khanna MBBS, FRCR, Abstract Co-Author: Nothing to Disclose

Marshall Stephen Sussman PhD, Abstract Co-Author: Nothing to Disclose

Ravi Menezes PhD, Abstract Co-Author: Nothing to Disclose

Brent Graham, Abstract Co-Author: Nothing to Disclose

Dimitri Anastakis MD, Abstract Co-Author: Nothing to Disclose

Ali M. Naraghi FRCR, Abstract Co-Author: Nothing to Disclose

To evaluate Diffusion Tensor Imaging (DTI) indices of the median nerve before and after carpal tunnel release in patients with carpal tunnel syndrome to determine whether indices acquired prior to surgery differ from those acquired postoperatively.

After IRB approval, 10 patients with a clinical diagnosis of carpal tunnel syndrome were prospectively recruited. Eight patients completed the study (7 women, 1 man; mean age 67 years). All patients had bilateral asymmetric symptoms, with subsequent decompression surgery of the more symptomatic side. DTI of both wrists was performed using single-shot spin-echo-based echo-planar imaging (TR/TE, 7.000/103 ms; b value 1,025 s/mm²) preoperatively, and 6 months after unilateral carpal tunnel release. Postprocessing evaluation of the median nerve at the level of the mid pisiform included fiber tractography, quantitative analysis of fractional anisotropy (FA) and apparent diffusion coefficient (ADC). One investigator blinded to clinical data, side and time point relative to surgery performed all analyses.

All 8 patients had surgical decompression of the right carpal tunnel with resolution of symptoms in all patients at 6 months postoperatively. A statistically significant increase in FA (Mean preop 0.401; Mean 6 mos postop 0.453; p=0.025) and decrease in ADC (Mean preop 00.00140 ; Mean 6 mos postop 0.00125; p= 0.017) was found at 6 month post surgery as compared to preoperative baseline values on the operative side. No statistically significant difference was found in DTI indices (FA and ADC), of the non-operative median nerve between baseline and postoperative evaluation.

A statistically significance increase in FA and decrease in ADC values of the median nerve are seen following surgery (paralleling resolution of clinical symptoms) in patients with carpal tunnel syndrome.

DTI indices of the median nerve improve following surgical decompression and DTI may be a useful tool in monitoring patients following carpal tunnel release.

Gama Lobo, L, White, L, Khanna, M, Sussman, M, Menezes, R, Graham, B, Anastakis, D, Naraghi, A, Diffusion Tensor Imaging of the Median Nerve before and after Carpal Tunnel Release in Patients with Carpal Tunnel Syndrome: Feasibility Study.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034491.html