Fast Low-Angle Dual Spin-Echo (FLADE): A New Pulse Sequence for Micro-Imaging of Trabecular Bone
Magland J, Vasilic B, Wehrli F
University of Pennsylvania Medical Center
A new pulse sequence for high-resolution imaging of trabecular bone (TB) at distal extremities is described. Spin echo approaches such as 3D FLASE (Fast Large-Angle Spin-Echo) have proven useful for micro-imaging of TB, as they are less sensitive to artifacts from local susceptibility induced gradients in the vicinity of trabeculae. However, the short repetition time (TR) needed to achieve sufficient resolution within a clinically feasible scan time can cause problems. In FLADE (Fast Low-Angle Dual Spin-Echo), the single spin-echo of FLASE is replaced by a double spin-echo, and the TR is significantly lengthened. The longer TR not only reduces artifacts, but can also be used to improve the detection of patient motion.