Imaged-guided therapy for minimally invasive surgeries and interventions is provided. An image-guided device includes an elongate tubular member, such as a catheter, an annular array of capacitive micromachined ultrasound transducers (cMUTs) for real-time three-dimensional forward-looking acoustic imaging, and a therapeutic tool. The therapeutic tool is positioned inside an inner lumen of the elongate tubular member and can be a device for tissue ablation, such as a high intensity focused ultrasound (HIFU) device or a laser. The HIFU device is operable at high frequencies to have a sufficiently small focus spot, thus a high focal intensity. The imaging annular array is also operable at high frequencies for good acoustic imaging resolution. The high resolution forward-looking imaging array, in combination with the high frequency HIFU transducer, provides a single image-guided therapy device for precise tissue ablation and real-time imaging feedback.