Differentiation between Tuberculous Spondylitis and Pyogenic Spondylitis on MR Imaging

OBJECTIVE: The objective of this study was to compare the magnetic resonance (MR) imaging of tuberculous spondylitis with pyogenic spondylitis. METHODS: MR images of the spines of 41 patients with infectious spondylitis at our institution over 8-years of period were retrospectively reviewed. Eighteen patients with infective spondylitis were excluded because their results on the marrow biopsy and culture were negative. MR imaging findings in 6 patients with tuberculous spondylitis (3 male, 3 female) were compared with those of 17 patients (10 male, 7 female) with pyogenic spondylitis. RESULTS: Two MR imaging findings were statiscally significant in differentiating the tuberculous spondylitis from pyogenic spondylitis: a well defined paraspinal abnormal signal and a thin and smooth abscess wall. There were no significant differences in the following MR imaging findings: paraspinal abscess or intraosseous abscess, subligamentous spread to three or more vertebra, involvement of multiple vertebra, hyperintense signal on T2-weighted images, heterogenous low signal on T1-weighted images, involvement of posterior element, epidural extension, involvement of intervertebral disk, disk space narrowing, rim enhancement of the abscess, skip lesion, and endplate destruction. CONCLUSION: MR imaging is an appropriate modality for differentiation of tuberculous spondylitis from pyogenic spondylitis.