Bicipital aponeurosis (BA) transverse view. The BA (white arrowheads) is seen as double contour bridging the brachial artery (red dashed oval) and the median nerve (yellow arrowhead) before it connects to the antebrachial fascia that covers the pronator teres muscle (orange arrowhead). Note that, due to anisotropy, the biceps tendon is not delineated here in contrast to Fig. 4. BR brachialis muscle (color figure online)