Assessment of median nerve with magnetic resonance neurography  in cases with carpal tunnel syndrome  and controls

Ghasem  Farahmand; Atefeh  Behkar; Hassan  Hashemi; Mahsa  Ghajarzadeh; Samira  Raminfard; Mojtaba  Shahbazi; Payam  Sarraf

doi:10.18502/cjn.v23i2.16837

Ghasem Farahmand Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
Atefeh Behkar Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
Hassan Hashemi Radiology Ward, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
Mahsa Ghajarzadeh Brain and Spinal Injury Repair Research Center, Tehran University of Medical Sciences, Tehran, Iran
Samira Raminfard Advanced Medical Technologies and Equipment Institute, Tehran University of Medical Sciences, Tehran, Iran
Mojtaba Shahbazi Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
Payam Sarraf Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/cjn.v23i2.16837

Keywords: Carpal Tunnel Syndrome; Magnetic Resonance Imaging; Diffusion Tensor Imaging

Abstract

Background: Carpal tunnel syndrome (CTS) is a common peripheral nerve entrapment disorder that is diagnosed using clinical signs and symptoms and confirmed via nerve conduction studies (NCSs). While NCS is a semi-invasive procedure, magnetic resonance imaging (MRI) is a non-invasive diagnostic tool that detects macroscopic nerve abnormalities and evaluates a patient's surgical or medication treatment options. This study assessed magnetic resonance neurography (MRN)’s diagnostic and grading value by comparing it to electrodiagnostic studies in patients with CTS and healthy individuals.

Methods: This was a cross-sectional study on 27 wrists with CTS and 27 healthy wrists. After history taking and physical examination, we employed an NCS to confirm and determine the severity of CTS, then MRN and diffusion tensor imaging (DTI) were used to calculate apparent diffusion coefficient (ADC), fractional anisotropy (FA), and cross-sectional area (CSA).

Results: 18 patients with CTS (27 median nerves) and 15 healthy controls (27 median nerves) were evaluated. The mean FA in the CTS group was significantly lower (0.38 ± 0.05 vs. 0.45 ± 0.06, P < 0.001).The mean CSA and ADC were higher in patients with CTS but not statistically significant. FA’s diagnostic cut-off was 0.42, with a sensitivity of 70.4% and a specificity of 63%.

Conclusion: MRN with DTI can be an effective and non-invasive diagnostic technique for the detection of CTS. The FA measure demonstrated adequate sensitivity and specificity for differentiating patients with CTS from healthy individuals.