Quantitative MRI Evaluation of the Supraspinatus-Deltoid Muscle Force Couple with T2* Mapping

Motivation: No previous studies have evaluated relative supraspinatus-deltoid force couple (Supra-Delt-FC) muscle T2*-metrics or considered their potential as biomarkers for Supra-Delt-FC functionGoal(s): Evaluate/compare Supra-Delt-FC T2*-values within 6 supraspinatus injured-case, and 6 (age/sex matched) uninjured-control subjectsApproach: Unilateral, 3T, 3D-Cones, 15-echo-UTE MRI acquisitions were utilized for calculation and evaluation of Supra-Delt-FC muscle T2*-valuesResults: Independent evaluations of deltoid and supraspinatus muscle T2*-values revealed no significant differences between injured-case and uninjured-control subjects. However, evaluation of relative T2*-metrics (mean difference & FC-ratios) revealed significant case-to-control differences – suggesting that relative supraspinatus-to-deltoid T2* metrics may be more sensitive to alterations in Supra-Delt-FC and shoulder function following injuryImpact: While independent comparisons of respective supraspinatus and deltoid muscle T2*-values revealed no significant case-to-control differences, relative Supra-Delt-FC muscle T2*-metrics were significantly different between groups. Results suggest that relative Supra-Delt-FC muscle T2*-metrics may be more sensitive to alterations in Supra-Delt-FC function.