Evaluation of perfusion-related and true diffusion in vertebral bone marrow: a preliminary study.

Our aim in this study was to obtain noninvasively more detailed information on perfusion and diffusion in vertebral bone marrow. We analyzed two diffusion components using a biexponential function. Eleven healthy volunteers were examined. By a 1.5-T MRI, we performed single-shot diffusion magnetic resonance imaging to acquire diffusion-weighted images (DWIs) with multiple b values. We determined perfusion-related diffusion and true diffusion coefficients (D* and D), the fraction of the perfusion-related diffusion component (F), and the apparent diffusion coefficient (ADC) in the lumbar vertebral body. Then, we compared these diffusion parameters with the bone mineral density (BMD) obtained with dual-energy X-ray absorptiometry. Moreover, the fat fraction (FF) of the bone marrow was calculated by use of double gradient-echo images with and without spectral adiabatic inversion recovery in the same subject. The BMD showed a significant positive correlation with D*, whereas there was no significant correlation between the other diffusion parameters and BMD. There was a negative correlation between the D or ADC and FF, although no correlation was found between D* or F and FF. Diffusion analysis with a biexponential function made it possible to obtain detailed information on bone perfusion and diffusion in healthy young volunteers.