The aim of the study was to assess the diagnostic potential of diffusion tensor imaging (DTI) for pathologies of the peripheral nervous system (PNS) through clinical, electrophysiological and morphological evaluation of the median nerve.

The present work was a multilevel prospective study involving 30 subjects, 15 of whom had carpal tunnel syndrome (CTS) and 15 healthy controls. All subjects underwent clinical evaluation through administration of the Boston Carpal Tunnel Questionnaire (BCTQ), electroneurography (ENG), 3-Tesla magnetic resonance imaging with DTI, and calculation of fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) at the flexor retinaculum. Tractography was also performed for three-dimensional reconstruction of the route of the median nerve through the carpal tunnel. The degree of functional impairment was compared with the anatomical damage to the median nerve according to ENG and DTI.

FA and ADC were significantly correlated with ENG parameters of CTS and BCTQ data. Mean FA and ADC values in the CTS patients were 0.359±0.06 and 1.866±0.050×10⁻³mm²/s, respectively, vs 0.59±0.014 and 1.395±0.035×10⁻³mm²/s, respectively, in the controls. FA was decreased and ADC increased in patients with CTS compared with healthy controls (P<0.05).

DTI parameters were clearly confirmed by both clinical and ENG data and, therefore, may be used for the diagnosis of CTS.