Quantitative evaluation of diffusion-weighted imaging with multiple b-values in vertebral fractures

Abstract

Differentiating benign from malignant vertebral fracture is sometimes difficult in geriatric oncology patients. Accurate diagnosis is necessary for treatment planning. Therefore, we aimed to investigate the role of quantitative evaluation of diffusion-weighted imaging (DWI) at multiple b-values of 200, 400 and 600 s/mm2 in differentiating benign from malignant thoracolumbar vertebral fractures and to determine an optimal b-value. Methods: Forty-four patients with 72 vertebral fractures were enrolled. Magnetic resonance imaging (MRI) findings combined with DWI at b-values of 200, 400 and 600 s/mm2 were evaluated. Apparent diffusion coefficient (ADC) and normalized ADC values were obtained. Radiological and histopathological/ follow-up results were compared. Results: Of 72 vertebral fractures, 22 were benign and 50 were malignant. Mean ADC and normalized ADC values of malignant group were lower than benign group's in all b-values (p<0.05). Despite of no significant difference between ADC values at b-values of 200, 400 and 600 s/mm2 within each group, normalized ADC values were lower at b-value of 200 s/mm2 than those of at 600 s/mm2 in malignant group (p<0.05). Conclusion: MRI combined with DWI is a problem solving modality especially in geriatric oncology patients. Performing DWI at b-value of 200 s/mm2 and estimation of normalized ADC value for optimization of data are recommended.