Clinical application of MR diffusion tensor imaging in lumbar disc annulus fibrosus

Objective: To evaluate the clinical value of the diffusion tensor imaging (DTI) in lumbar' disc annulus fiber's diseases. Methods: Fifty six subjects including normal volunteer (n=10), patients with lumbar disc herniation (LDH) (n=24), and with herniated intervertebral disc (HID) (n22) were performed with MR scan. The DTIs were obtained in each subject. The DTI source images were sent to the work station and postprocessed Fiber Tracking (FT) picture, DCavg picture, and FA picture. Results: The normal disc annulus fibrosus presented a continuous and integrity circulus in FA picture and DCavg picture, the DCavg value and FA value were uniform, DCavg was(0.34±0.13) x 10-9 mm2/s; FA was 0.64±0.22. FT picture demonstrated the annulus fibrosus' appearance was continuous and integrity. The DCavg value and FA value in LDH group was (0.29 ± 0.10) x 10-9 mm2/s and 0.53 ± 0.22, they had no significant difference with normal group (P>0.05). Seven cases in LDH group and 9 cases in HID group were found in FT picture. The mean DCavg value in annulus fibrosus disruption was significantly larger (1.01 ± 0.10) x 10-9 mm2/s and the mean FA value (0.15 ± 0.03 )was significantly smaller than those in normal place (P<0.01). Conclusion: DTI can noninvasively display the lumbar disc anulus fibrosus's morphous and integrity and demonstrate anulus fiber disruption. As an effective supplement of conventional MRI, DTI can offer a precise guidance for treatment. (authors)