Figure 4. Figures 3, 4. (3) Drawing shows the coracoacromial arch, deltoid muscle, rotator cuff, and intervening subacromial-subdeltoid bursa. (4) Coronal (longitudinal) US image shows the hypoechoic subacromial-subdeltoid bursa (solid straight arrows) interposed between hyperechoic layers. The adjacent deltoid muscle (solid curved arrows) and the echogenic rotator cuff (open arrows) are also seen.