Quantitative Analysis of the Diffusion-Weighted Steady-State Free-Precession Signal in Vertebral Bone-Marrow Lesions

Olaf Dietrich¹, Andreas Biffar¹, Andrea Baur-Melnyk, Gerwin Schmidt, Maximilian F. Reiser¹

Diffusion-weighted steady-state free-precession (DW-SSFP) sequences are extremely valuable for the differential diagnosis of benign osteoporotic and malignant neoplastic vertebral compression fractures. The purpose of the present study was to provide a detailed theoretical and experimental analysis of the DW-SSFP signal in the spine. It could be demonstrated that the main reasons for the different lesion contrasts are an opposed-phase readout in combination with the differing fat fractions and T₂^*-values in the fractures as well as in normal-appearing VBM of both entities. The observed signal contrast is therefore rather fat- and T₂^*-weighted than diffusion-weighted.