Fig. 10

Cavernosal haematoma with an injury of the cavernosal artery and an arterio-lacunar fistula. A 26-year-old patient attended the emergency department for priapism after a perineal injury caused by a fall from a pedal bicycle. An emergent US was performed, showing in the sagittal plane in B-mode (a) and in microvascular imaging (MVI) mode (b) an abnormality of the proximal aspect of the right cavernous artery (arrow) with an outpouching, suggestive of pseudoaneurysm is demonstrated. On colour Doppler mode (c), the ‘yin-yang’ sign (arrow) is identified, representing circumferential flow within a pseudoaneurysm. In addition, elastography (d) shows a greater rigidity of the right corpus cavernosum (arrowhead), probably due to the higher blood content compared to the left corpus cavernosum. After administration of UCA (e), the injury to the cavernous artery (arrow) is demonstrated, as well as contrast extravasation and early filling of that portion of the right cavernous body, compatible with an arterio-lacunar fistula. The CT scan performed for polytrauma in the emergency department (f) shows early enhancement of the right corpus cavernosum compared to the left, as an indirect sign of an arterio-lacunar fistula