MR Imaging for the Differentiation of Early Infectious Spondylitis and Modic Type I Change in the Lumbar Spine

Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea Department of Preventive Medicine, School of Medicine, Kyung Hee University, Korea Received December 15, 2009 ; Accepted February 16, 2010 Address reprint requests to : Young Cheol Yoon, M.D., Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-dong, Kangnam-gu, Seoul 135-710, Korea. Tel. 82-2-3410-6454 Fax. 82-2-3410-0084 E-mail: [email protected] Purpose: To evaluate magnetic resonance (MR) imaging findings for the differentiation of early infectious spondylitis and Modic type I change in the lumbar spine. Materials and Methods: Contrast-enhanced lumbar spine MR images with bone marrow edema adjacent to the endplates of 25 patients (14 men, 11 women; mean age 53.7 years) were evaluated. Margin and enhancement in the bone marrow changes, erosion or destruction of endplates on T1-weighted sagittal MR images, T2 signal intensity and enhancement in the intervertebral disks, as well as the presence of paravertebral soft tissue were evaluated. The final diagnoses were 11 cases of infectious spondylitis and 14 cases of Modic type I change. Results: The margin of bone marrow changes was more blurred in infectious spondylitis than in Modic type I change. The endplates for infectious spondylitis showed destructions, and Modic change erosions. On postcontrast images, all the cases except for only one with degenerative disease were enhanced in the vertebral bodies. Intervertebral disks showed T2 hyperintensities and were enhanced in both the infectious spondylitis and Modic change. Paravertebral soft tissue was seen more commonly in infectious spondylitis. Conclusion: The useful findings of early infectious spondylitis include endplate destruction, blurred margins of the bone marrow changes on T1-weighted images, and the presence of paravertebral soft tissue.