Focus on Diffusion MR Investigations of Musculoskeletal Tissue to Improve Osteoporosis Diagnosis: A Brief Practical Review

Figure 2

Schematic representation of cancellous bone at different skeletal sites in healthy (top) and osteoporotic (bottom) cancellous bone. Fat content increases from axial skeleton to peripheral skeletal sites. As a consequence, water ADC is higher in the vertebrae and lower in the calcaneus. Indeed, diffusion of water in calcaneus is more restricted compared to water in femoral neck or in vertebrae. With the development of osteoporosis, two different and opposite mechanisms occur: an increase of the marrow fat which decreases the ADC value and a microstructure deterioration with a pore enlargement that increases ADC. In the calcaneus, only the last mechanism results (adapted from reference [43] with permission).