Fig. 23

Examples of pathologies of the medial antebrachial cutaneous nerve. A, B Short-axis views of the medial antebrachial cutaneous nerve in a patient with a traumatic injury to medial proximal arm. A At the axilla, the medial antebrachial cutaneous nerve is of average cross-sectional area and its echotexture is preserved. However, in B, a level of 15 cm proximal to the elbow, the nerve is enlarged and the internal nerve fascicles are swollen, mostly reflecting axonal and fascicular edema secondary to axonal nerve lesion. C,D Short-axis and long-axis views of the medial antebrachial cutaneous nerve in a patient with bullet injury to the medial arm which resulted in neuroma-in-continuity. C shows hypoechoic swelling of the nerve. D shows the neuroma in the longitudinal view appearing as a fusiform hypoechoic swelling in continuity with the nerve