MRI DWI/ADC signal predicts shrinkage of lumbar disc herniation after O2–O3 discolysis.

PURPOSE: Evaluate the discal morpho-structural changes as a predictive sign in the clinical outcome after ozone therapy in lumbar disc herniation using the T2-shine through effect in diffusion-weighted imaging (DWI). METHOD: One hundred and fifty-four patients suffering from lumbosciatica (89 men and 65 women; age range, 23-62 years) were included, previous MR study performed with FSE-T2 and T2-fat, SE-T1 and DWI sequences, and were randomly assigned to two groups. Seventy-seven patients (control group) underwent conservative treatment with intraforaminal injection of steroid and anaesthetic. The remaining 77 patients (study group) underwent the same treatment with the addition of oxygen-ozone (O2-O3). During the following six months, a MRI follow-up with the same sequences was performed. An intervertebral disc volumetric analysis (IDVA), DWI signal score and post treatment clinical outcome evaluation were performed for an assessment of hernia reduction. χ² test, Student's t test and analysis of covariance were used for comparison of variables. RESULTS: In the study group, 58 of 77 patients had a successful outcome (responders). In the responders group, DWI T2-shine through effect was present during MRI follow-up and in particular in 53 of 77 patients in six months of follow-up (p < 0.05). Moreover, in the same group a statistically significant disc shrinkage was shown by IDVA in sixth months of follow-up (p < 0.05). CONCLUSIONS: T2-shine through effect in DWI is present before morphological disc reduction and moreover could be considered as a predictive sign of response to oxygen-ozone treatment.