Poster 173: Comparison of Sensitivity of Diagnosis of Subscapularis Tear on 1.5 Tesla versus 3.0 Tesla Magnetic Resonance Imaging

OBJECTIVES: Diagnosis of subscapularis tears via Magnetic Resonance Imaging (MRI) has been reported to have variable accuracy, with prior studies indicating sensitivity of MRI ranging from 30.0-83.0%. In the current literature, studies utilizing 3.0T MRI scans have generally shown higher sensitivity compared to studies utilizing 1.5T MRI scans; however, there has not been direct comparison of differences in accuracy of 1.5 vs. 3.0T for diagnosis of subscapularis tear. The aim of this study is to investigate this difference. We hypothesize that 3.0T MRI scans will show higher sensitivity for the detection of subscapularis tears compared to 1.5T MRI scans. METHODS: A single institution data set was queried to identify patients undergoing rotator cuff repair between January 2015 and January 2020. Patients were separated based on 1.5T and 3.0T MRI strength and these cohorts were analyzed based on intraoperative findings of subscapularis tears and interpretation of these MRI reports. Likewise, demographic information of the cohorts was analyzed including BMI, age, and sex. Univariate analysis, multivariate analysis, and Pearson’s χ(2) test, Mann- Whitney U test were used when appropriate. RESULTS: In a total 756 of patients, 151 were identified as having rotator cuff surgery with preoperative MRI that met our inclusion criteria. A total of 50 (33.1%) of patients were identified as having intraoperative findings of subscapularis tears that were not appreciable on MRI. A statistically significant difference was found when comparing the sensitivity of 3.0T MRI for identifying subscapularis tears when compared to 1.5T MRI. 3.0T MRI had a sensitivity of 72.9% compared to 56.4% respectively[TTW1] [GIM2] (P < 0.05). Both groups had a PPV of 100% given no false positive results. 3.0T MRI had a NPV of 92.5% while 1.5T had a NPV of 92.2%. CONCLUSIONS: When a subscapularis tear is clinically suspected, surgeons should be critical over the choice of 1.5T vs 3.0T MRI imaging and understand their sensitivity to guide recommendations for intervention, preoperative planning, and overall patient satisfaction.