A 45 to 55 MHz needle-based ultrasound system for invasive imaging.

The design, construction and fabrication of a high frequency needle-based ultrasound imaging system is described. A miniature lead zirconate titanate transducer was mounted opposite a parabolic mirror in a stainless steel needle. By inserting the needle into a tissue, a cross section image of the tissue can be made. Two needle probes were built, a 45 MHz 2.8 mm diameter probe with 125 microns lateral, 55 microns axial resolution and a 55 MHz 1.6 mm diameter probe with 105 microns lateral, 40 microns axial resolution. Preliminary phantom and in vitro tissue images demonstrate the feasibility of high frequency needle-based imaging.