Determining the Validity and Reliability of Elastographic Analytics Using Rotator Cuff Muscles

Abstract

The purpose of this study was to determine the feasibility and reliability of using elastography and subsequent image analysis to evaluate two rotator cuff muscles. Elastography imaging was conducted on the infraspinatus muscles of four cadavers. Next, elastography imaging was conducted on the supraspinatus muscles of 10 human subjects. Image analysis was conducted retrospectively to determine the relative computed strain value. Pearson correlations and two-tailed t tests for equal variance were used to demonstrate an interclass correlation (ICC) for two researchers performing image analysis. A significance value of P < .05 was set a priori. In the cadaver portion of the study, a Pearson correlation had an r = 0.99, and a two-tailed t test for equal variance showed P = .08. In the human portion of the study, a Pearson correlation had an r = 0.92, and a two-tailed t test for equal variance yielded a P < .05. When all elastography images from both portions of the experiment were combined, the analysis showed an r = 0.97 and a P < .05. This descriptive research study provides lower level scientific evidence that steady-state quasi-static elastography could provide valid and reliable information that will assist in the evaluation of the rotator cuff muscles of the shoulder.