Diffusion magnetic resonance imaging to differentiate degenerative from infectious endplate abnormalities in the lumbar spine.

STUDY DESIGN: A retrospective observational study of healthy volunteers and patients with degenerative and infectious endplate abnormalities in the lumbar spine.

OBJECTIVES: Our purpose was to evaluate the usefulness of diffusion-weighted imaging (DWI) for the differentiation of degenerative and infectious endplate abnormalities using 1.5-T magnetic resonance imaging (MRI).

SUMMARY OF BACKGROUND DATA: DWI can provide valuable structural information about tissues that may be useful for clinical applications in differentiation between degenerative and infectious endplate abnormalities.

METHODS: Sixteen consecutive patients with endplate abnormalities that was detected by MRI of the lumbar spine, and 15 healthy volunteers were studied. DWI was performed using whole-body imaging with background body signal suppression with a b value of 1000 s/mm2. Apparent diffusion coefficient values of normal and abnormal vertebral bone marrow were calculated.

RESULTS: Twenty-nine vertebral abnormalities were found in 16 patients. Nine vertebral abnormalities in 5 patients were because of infections and 20 vertebral abnormalities in 11 patients were because of degenerative changes; 7 levels were classified as Modic type 1, 7 levels as type 2, and 6 levels as type 3. DWI showed hyperintensity in all patients with infection, similar to that used in positron emission tomography, but not in the intervertebral spaces of any patients with degenerative disease. Apparent diffusion coefficient values of infectious bone marrow were significantly higher than normal and degenerative bone marrow.

CONCLUSION: DWI is useful for differentiation of degenerative and infectious endplate abnormalities. Moreover, MRI is widely used clinically because of the lack of ionizing radiation, low cost, and fast imaging time as compared with positron emission tomography. Therefore, DWI has the potential to be used as a screening tool.