INTRODUCTION: The purpose of this study was to evaluate the usefulness of Diffusion‐weighted imaging (DWI) for the differentiation of degenerative and infectious endplate abnormalities in the lumbar spine using 1.5‐tesla magnetic resonance (MR) imaging.
METHODS: 16 consecutive patients with endplate abnormalities detected by MR imaging of the lumbar spine and 15 healthy volunteers were enrolled in the study. DWI was performed using a whole body imaging with a background body signal suppression (DWIBS) with b value of 1000 s/mm2. Apparent diffusion coefficient (ADC) values of normal and abnormal vertebral bone marrow were calculated.
RESULTS: A total of 29 vertebral abnormalities were found in 16 patients. 9 vertebral abnormalities in 5 patients were due to infections and 20 vertebral abnormalities in 11 patients were due to degenerative changes and 7 levels were classified as Modic type1, 7 levels as type2, and 6 levels as type3. DWI showed hyperintensity in all 9 levels with infection, similar to that used in positron emission tomography (PET), but not in the intervertebral spaces of any patients with degenerative disease. Mean ADC (×10‐3 mm2/s) values were 0.453 in normal marrow, 1.067 in infectious marrow, 0.624 in Modic type1, 0.500 in Modic type2, and 0.756 in Modic type3. Mean ADC values of infectious bone marrow were significantly higher than normal and degenerative marrow (p<0.001).
DISCUSSION: Spinal infections are now more frequently. Differentiation between degenerative and infectious endplate abnormalities is occasionally difficult. Several studies have reported that PET was sensitive in diagnosing spinal infection. Our findings suggest that DWI is useful for differentiation of degenerative and infectious endplate abnormalities, similar to PET. Moreover MRI is widely used clinically because of the lack of ionizing radiation, low cost and fast imaging time as compared with PET. Therefore, DWI has the potential to be used as a screening tool.