Tracking motion with tagged rapid gradient‐echo magnetization‐prepared MR imaging

A technique for rapid assessment of tissue motion was developed by combining spatially selective radio‐frequency tagging pulses with centric phase‐encoding view ordering in a T1‐weighted, magnetization‐prepared gradient‐echo acquisition sequence. This sequence allowed labeling and tracking of tissue motion with single‐image acquisition times of less than 3 seconds. Multiple tagged bands 3 mm thick were superimposed orthogonal to the imaging plane. Motion in the interval between tagging and the start of image acquisition could then be precisely determined. The technique was evaluated with phantom studies and then applied to human volunteers for assessment of skeletal muscle motion, phonation, and pelvic floor motion.