Experimental verification of the sectored annular phased array for MRI guided ultrasound surgery

To meet two of the requirements for MRI Guided Ultrasound Surgery, namely small surgical equipment and large focal volumes, a combined array encompassing the design parameters of the concentric-ring array and the sector-vortex array has been proposed. Simulations will show that the sectored annular array is capable of producing larger necrosed tissue volumes than the concentric-ring alone, while maintaining the ability of the concentric-ring array to move the focal volume in the axial direction of the array. These simulations are verified by measurements of the acoustic fields produced by an experimental array in water. In addition, the constructed array produced the necessary power required to coagulate tissue in rabbit thigh in vivo, while the temperature elevation was monitored using MRI.