Ultrasound applicators able to both image a treatment site and administer ultrasound therapy include an array of transducer elements that can be focused. In several embodiments, an electronically phased array is used for controlling the focal point of an ultrasound beam. The ultrasound beam produced thereby can also be electronically steered. To reduce the quality factor or Q of the array when the array is used for imaging, an electronic switch is selectively closed, placing a resistance in parallel with each of the array elements. A flexible array is employed in several embodiments and is selectively bent or flexed to vary its radius of curvature and thus control the focal point and/or a direction of focus of the array. In another embodiment, each of the transducer elements comprising the array are individually mechanically pivotable to steer the ultrasonic beam produced by the transducer elements.