Evaluation of Vertebral Bone Marrow with Diffusion Weighted MRI and ADC Measurements

Objective: The purpose was to determine the usefulness of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) in the evaluation of vertebral bone marrow. Methods: Patients were divided into; osteoporotic, traumatic, infectious spondylitis, hemangioma, malignancy and non-osteoporotic groups. Seventy-four patients (45 women and 29 men; mean age, 58 years; range 17-89) were investigated in this study. Conventional magnetic resonance imagining (MRI) sequences and SE-EPI sequence with b- value of 600 s/mm(2) were used. Qualitative and quantitative evaluation with DWI and ADC was carried out for each fractured vertebra and randomly chosen normal vertebrae. A p-value of <0.05 was considered significant. Results: The mean DWI and ADC values of normal vertebrae was found to be 142.5 +/- 100 and 0.48 +/- 0.1x10(-3) mm(2)/s, respectively. A total of 103 fractures were encountered in 74 patients and L1 was the most commonly fractured vertebra (20 fractures, 19.4%). DWI and ADC qualitative assessment of fractures showed no significant difference between groups. The mean DWI and ADC values of fractured vertebrae was found to be 284.3 +/- 255.8 and 1.35 +/- 0.39x10(-3) mm(2)/s, respectively, which were significantly higher than that of normal vertebrae (p<0.05). The mean DWI value of normal vertebrae (76.2 +/- 37.3) and fractured vertebrae (124.5 +/- 87.6) in osteoporotic patients were significantly lower than that of non-osteoporotic patients (172.4 +/- 105.6 and 359.6 +/- 274.3) (p<0.05). Conclusion: DWI and ADC quantitative evaluation can differentiate fractured vertebrae from normal vertebrae, but qualitative assessment of fractures cannot distinguish between groups. DWI with quantitative assessment is helpful in the differential diagnosis of osteoporotic fractures from malignant fractures and also osteoporotic normal vertebrae from non-osteoporotic normal vertebrae, but ADC values are unhelpful.