3 During aspiration, a butterfly needle (19 or 21 gauge) is inserted into either the ... If the procedure is undertaken, a biopsy of corporal tissue should be obtained to confirm end-stage ...

biopsy of a perineal lesion. A: Ultrasound showing the same collection seen on MRI. B: Drainage performed via the transperineal approach. Note the 18-gauge Chiba needle (lower arrow), used for ...