ROLE OF DIFFUSION – WEIGHTED MAGNETIC RESONANCE IMAGING IN CHARACTERIZATION OF VERTEBRAL BONE MARROW PATHOLOGICAL LESIONS

Abstract

AIM: To evaluate the role of diffusion weighted magnetic resonance imaging in characterization of vertebral bone marrow pathological lesions. MATERIALS AND METHODS: Forty patients with bone marrow abnormal MRI signal intensity were enrolled in the study and upon MRI finding they wear grouped into four groups. DWI was performed with b values of 0and 500 s/ mm2. Results of the histo-pathological evaluation or MRI follow up or isotope were compared with the DWI results. Apparent diffusion coefficient (ADC) values were calculated. RESULTS: All cases of malignant collapse (4 cases 10%) were hyper intense on DWIs and hypo intense on ADC map with mean ADC (0.8 ± 0.33 x 10−3 mm2/s). All benign osteoporotic collapse cases (7 cases 17.5%) were hypo intense (3 cases) or iso to hypo intense (4 cases) on DWIs and all wear hyper intense on ADC with mean ADC (1.64 ± 0.33 x 10−3 mm2/s). Twelve cases with endplate changes, the eight infectious spondylitis recorded mean ADC value (1.03 ±0.33× 10−3mm2/s). The remaining, 4 cases (10 %) with degenerative Modic I end plate changes recorded ADC value (1.76 ±0.33× 10−3mm2/s). Also (3 cases) malignant bone marrow infiltration without collapse were hyperintense on DWIs and hypointense on ADC map with mean ADC (0.8 ± 0.33 x 10−3 mm2/s). The mean ADC in hemangioma was (1.9 ± 0.33 x 10−3 mm2/s) and in ABC (1.93 ± 0.33 x 10−3 mm2/s). DW study of 4 cases respond to therapy recorded mean ADC value (1.64 ±0.33× 10−3mm2/s), however, the 2 cases with residual viable tumor tissue record (0.79 ±0.33× 10−3mm2/s). DWI and ADC values have high sensitivity and specificity in differentiating benign from malignant lesions and in post therapy follow up. CONCLUSIONS: DWI with quantitative ADC measurements Using b value (b=500 s / mm2) can be useful in differentiating benign from malignant bone marrow lesions, differentiated between causes of end plate changes and be used in post therapy follow up. Keywords: Diffusion weighted imaging; Bone marrow; Vertebral compression fractures; Osteomyelitis; Therapy monitoring.