| Popis: |
Spongy-bone is a porous system characterized by a solid trabecular network immersed in bonemarrow and characterized by a different relative percentage of water and fats. In our previous paper, we demonstrated using calf bone samples, that water is more prevalent in the boundary zone while fats are rearranged primarily in the central zone of each pore. Moreover we showed that water internal gradient (Gi) magnitude from the samples was directly proportional to their trabecular bone density. Using a 9.4T MR micro-imaging system, here we evaluated T2, T2*, apparent diffusion coefficient (ADC) and Gi parameters from in vitro calf samples in spatially resolved modality, for both water and fat components. Moreover, relative percentages of water and fats were quantified from spectra. T2, T2* and ADC values are higher in fat than in water component. Moreover, the differential effects of fat and water diffusion result in different T2 and Gi behaviours. Our results suggest that differently from fat parameters, water T2*, ADC and Gi, may be reliable markers to assess not only trabecular bone density but, more generally, the status of spongy bone. |
