DIFFERENTIAL-DIAGNOSIS OF EROSIVE OSTEOCH ONDROSIS AND BACTERIAL SPONDYLITIS IN MRI

Purpose: To evaluate retrospectively criteria in the differential diag nosis of erosive osteochondrosis (EO) and infectious spondylitis (IS) on the basis of MRI. Methods: T-1-weighted sagittal images before and after Gd-DTPA application, T-2-weighted TSE or T-STIR images of 23 pat ients with proven IS and 41 patients with EO were evaluated. Criteria for this evaluation were morphology and extension of bone marrow edema , visibility of the low-intensity vertebral endplate, contrast enhance ment and signal intensity in the disc space on T-2-weighted and T-STIR images. Results: Bone marrow edema was more extensive in IS than in E O. The mean rated value for bone marrow edema on a four-level scale (0 -3) was for IS 2.91 (+/- 0.29), for EO 1.32 (+/- 0.76, p < 0.001). In 37/41 cases of EO and in 22/23 cases of IS Gd-DTPA enhancement was fou nd in the disc space (n. s.). In EO the low intensity endplate was vis ible in all parts in 36/41 cases (87.8 %) on T-1-weighted images, in I S not in a single case (0%). On T-2-weighted or STIR images signal int ensity of the discs was decreased in 82.1% of EO, 82.6% of segments in IS had water-equivalent signal intensity (p<0.001). Conclusion: If al l the criteria are taken into consideration differential diagnosis of EO and IS on the basis of MRI findings is possible.