A probe (40) includes a shaft (52) on which an ultrasound element (42) is mounted. An outer sheath (64) and an acoustic membrane (66) surround the shaft and the ultrasound element such that the shaft and ultrasound element are rotatable therein. Passages (56) supply a cooling and acoustic coupling fluid to an inlet and outlet (48) adjacent the acoustic element to cool the acoustic element and fill a volume between the acoustic element and the acoustic sheath with the fluid. A balloon (90) mounted on the probe is selectively inflated in order to fix a position of the probe. A drain (94, 98) drains urine and other bodily fluids through the probe.
