An ultrasound medical system includes a tube and resiliently flexible fingers. The tube has a distal end insertable into a patient and has a lumen with a distal opening. The fingers are extendable out of the distal opening of the lumen creating a deployed state and are at-least-partially retractable into the distal opening of the lumen creating a stowed state. Each finger includes an ultrasound transducer, wherein the distance between the transducers of adjacent fingers is greater in the deployed state than in the stowed state. In one example, at least one of the transducers is an ultrasound imaging transducer, an ultrasound medical-treatment transducer, or an ultrasound imaging and medical-treatment transducer.