UTE-Based DW-SSFP for Musculoskeletal MRI

Motivation: Fiber tracking of ligaments suffer from a low signal due to their fast T2 relaxation during a long echo time in spin-echo EPI diffusion sequences. Goal(s): Shorten the echo time of the diffusion sequence and acquire in 3D. Approach: Use a 3D spiral-in readout in a DW-SSFP sequence. Results: The 3D spiral-in readout features an enhanced signal, shorter TR or TE, a wider interval for diffusion gradients, reduced geometric distortion, and a minimized echo time shift. It is demonstrated for tracts of knee ligaments using ex vivo hind limbs of piglets. Impact: The proposed diffusion imaging sequence provides a high sensitivity to musculoskeletal tissue with short T2 relaxation times. This will be useful in studying the muscles, tendons, ligaments, and cartilage.