Analysis of Neuropathic Pain Using Magnetic Resonance Imaging T2 Mapping of Intervertebral Disc in Chronic Low Back Pain

STUDY DESIGN: Cross sectional study. PURPOSE: The study aimed to analyze mechanisms underlying chronic low back pain (CLBP) using magnetic resonance imaging (MRI) T2 mapping of the intervertebral disc (IVD). OVERVIEW OF LITERATURE: MRI T2 mapping utilizes the T2 values for quantifying moisture content and collagen sequence breakdown. We previously used MRI T2 mapping for quantifying the extent of IVD degeneration (IVDD) and showed a correlation between the degeneration of the posterior annulus fibrosus (AF) and CLBP. METHODS: We enrolled 40 patients with CLBP (17 males, 23 females; mean age, 50.8±1.6 years; range, 22–60 years). IVDs were categorized as the anterior AF, nucleus pulposus (NP), and posterior AF, and T2 value for each disc was measured. T2 values, assessed using the Japanese neuropathic pain (NeP) screening questionnaire, of the NeP and nociceptive pain (NocP) groups were compared. RESULTS: T2 values of the NocP and NeP groups were 64.7±5.6 ms and 58.1±2.3 ms for the anterior AF; 67.0±4.6 ms and 59.6±2.1 ms for NP; and 70.7±4.6 ms and 51.0±1.2 ms for the posterior AF, respectively. T2 values for IVDD were significantly lower in the NeP group than those in the NocP group (p<0.01). CONCLUSIONS: The results indicate a correlation between the degeneration of posterior AF and NeP. MRI T2 mapping may be beneficial for detecting NeP caused by IVDD and can help formulate targeted analgesic therapies.