DIFFERENCES OF MRI FEATURES BETWEEN TUBERCULOUS AND BACTERIAL SPONDYLITIS IN A TB-ENDEMIC AREA.

Pyogenic and tuberculous spondylitis are common causes of infectious spondylitis. The purpose of this study was to determine the specific MRI findings that can differentiate these two types of infectious spondylitis. This study retrospectively analyzed MRIs in patients diagnosed with infectious spondylitis from January 1, 2005 to December 31, 2009. Tuberculous spondylitis was diagnosed by histopathological findings of caseous granuloma, while pyogenic spondylitis was diagnosed by positive cultures of tissue, fluid, or blood. Locations and extents of the lesions, and the findings using individual imaging criteria were recorded. Statistical analysis was performed with the Fisher's exact test. A significant difference was considered at.p < 0.05. During the study period, 33 patients met the criteria. Of those, 24 patients had tuberculous spondylitis and nine had pyogenic spondylitis. Two suggestive findings for tuberculous spondylitis were abscesses with thin and smooth walls (75% in tuberculous spondylitis vs 0% in pyogenic spondylitis, p < 0.001) and well-defined paraspinal soft tissue (66.7% in tuberculous vs 11.1% in pyogenic spondylitis, p = 0.007). These two MRI findings may be helpful for differentiating between tuberculous and pyogenic spondylitis.