RT Journal Article SR Electronic T1 EP126 Comparative study on shear-wave elastography of the coracohumeral ligament between adhesive capsulitis and healthy controls: suggestion of cut-off value JF Regional Anesthesia & Pain Medicine JO Reg Anesth Pain Med FD BMJ Publishing Group Ltd SP A107 OP A108 DO 10.1136/rapm-2023-ESRA.188 VO 48 IS Suppl 1 A1 Lee, Yong-Taek A1 Park, Chul-Hyun YR 2023 UL http://rapm.bmj.com/content/48/Suppl_1/A107.abstract AB Background and Aims Pathologic changes in coracohumeral ligament (CHL) on MR or US is suggestive of diagnosis of adhesive capsulitis (AC). Objective is to compare the elasticity measured at the CHL between the patients with AC and healthy controls using shear wave elastography (SWE), and to suggest cut-off value.Methods This prospective study included 24 shoulders with clinical diagnosis of AC and 32 healthy shoulders. Longitudinal B-mode image and SWE of CHL were obtained in axial oblique plane on the lateral border of the coracoid process. In between-group comparison, thickness and elasticity of CHL in patient group obtained with maximal ER were compared with those of healthy group obtained with maximal ER and with 30° ER, respectively. Cut- off value and inter-/intra-rater reliability were calculated by ROC analysis and ICC, respectively.View this table:Abstract EP126 Table 1 Baseline demographicsView this table:Abstract EP126 Table 2 Comparison of CHL elasticity and thickness between subjects with adhesive capsulitis and healthy groupAbstract EP126 Figure 1 Validity of elastic modulus of CHL on shear wave elastography for differentiating adhesive capsulitis using ROC analyses. CHL; coracohumeral ligament, AUC ; area under the ROC curve, ROC ; receiver operating characteristicResults Baseline characteristics were similar between two groups (table 1). Elasticity of CHL with maximal ER was similar between two groups. However, elasticity of CHL with maximal ER in patient group were significantly higher than those of CHL with 30° ER in healthy group (table 2). Cut-off value of CHL elasticity in 30° ER was 107.4 (figure 1). SWE showed good inter-rater reliability and intra-rater reliability for CHL elasticity (with 30° ER, ICC 0.662 and 0.514; with maximal ER, ICC 0.660 and 0.506).Conclusions Shear wave elastography can show increased tissue elasticity of CHL in adhesive capsulitis of shoulder compared to healthy group with good intra- and inter-rater reliability. Also, the optimal cut-off value of CHL elasticity to predict adhesive capsulitis was presented.