A new technique for detecting waves parallel to muscle fibers in MR elastography: Application to the supraspinatus muscle

Motivation: In skeletal muscle MRE, shear wave propagation is anisotropic, which complicates stiffness estimation and often requires subjective manual methods with limited measurement accuracy. Goal(s): To improve the reliability of stiffness estimation and measurement by reducing anisotropic effects in skeletal muscle MRE. Approach: We developed fiber wave analysis (FWA), a technique that detects waves along muscle fibers and automates stiffness measurement. This method was tested on the supraspinatus muscle of healthy volunteers. Results: FWA showed clear wave propagation along muscle fibers and higher displacement values than conventional methods; the automatically defined area for stiffness measurements matched well with the area of clear wave propagation. Impact: Our technique enhances the reliability of skeletal muscle MRE by extracting waves along the muscle fiber direction and automating stiffness measurements. This advancement enables accurate assessment of pathological and physiological changes, supporting early diagnosis and better assessment of musculoskeletal disorders.