Design and evaluation of linear intracavitary ultrasound phased array for MRI-guided prostate ablative therapies

In this study, a linear, transrectal, ultrasound phased array capable of ablating large tissue volumes was fabricated and evaluated in tissue. The device was designed to be MRI compatible for use with MRI thermometry and guidance. The intracavitary applicator increases the treatable tissue volume by utilizing an ultrasonic motor to provide up to a 100-degree mechanical rotation angle to a 62-element 1D aperiodic ultrasound array. MRI guided in vivo and ex vivo experiments were performed to verify the array's large volume ablative capabilities. The array generated 3 cm/spl times/2 cm/spl times/2 cm lesions with 8-12 half-minute sonications equally spaced in the volume. The results indicate that transrectal ultrasound coagulation of the whole prostate is feasible with the method developed.