Ultrasound to Predict the Prognosis of Rotator Cuff Tears

This diagnostic test would be executed by a physician who has experiences of using Siemens Acuson S2000 ultrasound system for more than three year. The examination includes two of four rotator cuff muscles, listed as follows, supraspinatus muscle and infraspinatus muscle. Linear transducer (4-9 MHz) would be used for the whole test. The probe would be positioned along the longitudinal axis of the muscle belly. Compressive sonoelastography technique is used for semiquantitative analysis. In order to maintain the quality of images, quality factor needs to be over or equal to 60. The quantitative analysis was performed by shear wave sonoelastography and the region of interest (ROI) would be divided into four quadrants. The physicians will measure the shear wave velocity at the center point of each quadrant.