In-vivo T2-relaxation times of asymptomatic cervical intervertebral discs

Limited research exists on T2-mapping techniques for cervical intervertebral discs and its potential clinical utility. The objective of this research was to investigate the in-vivo T2-relaxation times of cervical discs, including C2–C3 through C7–T1. Ten asymptomatic subjects were imaged using a 3.0 T MR scanner and a sagittal multi-slice multi-echo sequence. Using the mid-sagittal image, intervertebral discs were divided into five regions-of-interest (ROIs), centered along the mid-line of the disc. Average T2 relaxation time values were calculated for each ROI using a mono-exponential fit. Differences in T2 values between disc levels and across ROIs of the same disc were examined. For a given ROI, the results showed a trend of increasing relaxation times moving down the spinal column, particularly in the middle regions (ROIs 2, 3 and 4). The C6–C7 and C7–T1 discs had significantly greater T2 values compared to superior discs (discs between C2 and C6). The results also showed spatial homogeneity of T2 values in the C3–C4, C4–C5, and C5–C6 discs, while C2–C3, C6–C7, and C7–T1 showed significant differences between ROIs. The findings indicate there may be inherent differences in T2-relaxation time properties between different cervical discs. Clinical evaluations utilizing T2-mapping techniques in the cervical spine may need to be level-dependent.