A novel scan method using angled high frequency single element needle transducers

This paper proposes a new scan method for high frequency ultrasound (higher than 40 MHz) imaging. A needle transducer with a certain angled tip is inserted through a small incision hole and rotated around the axial direction to acquire sector or polar images of tissues deep inside the body where the conventional mechanical scanning cannot be performed. The feasibility of this novel technique was tested by computer simulation of wire phantom images and manually rotated scanning to image a polyimide tube with an unfocused 40-MHz PMN-PT needle transducer with a beveled tip of 45deg. The results indicate that the rotational scan imaging may expand the minimally invasive applications of high frequency ultrasound to other areas due to the closeness of the needle transducer to structures of interest buried in other tissues.