Devices, systems, and methods controllably cool blood vessels and other body lumens. The blood vessel will often be treated for atherosclerotic or other diseases by inflating a balloon so as to engage the surrounding luminal wall. Controlled cooling of the balloon effected by a change in phase of a cryogenic fluid within the balloon typically a change from a liquid phase to a gas phase can be provided with a controlled, gradual inflation of the balloon. A single control system can be used for any of a variety of alternative selectable balloon catheters having significantly differing cooling fluid flow characteristics.
