A catheter includes a catheter body (CB) having a CB proximal-portion, a CB distal-portion, and a CB lumen. The CB distal-portion has a CB distal end. The CB proximal-portion has a distally narrowing taper, wherein the CB distal-portion extends distally from the distally narrowing taper of the CB proximal-portion. The CB lumen extends through the CB proximal-portion and the CB distal-portion. An ultrasound transmission member (UTM) has a UTM distal end. The UTM extends longitudinally through the CB lumen. The UTM has a longitudinal taper that tapers toward the UTM distal end, and wherein the longitudinal taper tapers distally from the distally narrowing taper of the CB proximal-portion. A distal head (DH) is coupled with the UTM distal end and is disposed adjacent the CB distal end.