High-Frequency Ultrasound Array Designed for Ultrasound-Guided Breast Biopsy

This paper describes the development of a miniaturized high-frequency linear array that can be integrated within a core biopsy needle to improve tissue sampling accuracy during breast cancer biopsy procedures. The 64-element linear array has an element width of 14 μm, kerf width of 6 μm, element length of 1 mm, and element thickness of 24 μm. The 2-2 array composite was fabricated using deep reactive ion etching of lead magnesium niobate-lead titanate (PMN-PT) single crystal material. The array composite fabrication process as well as a novel high-density electrical interconnect solution are presented and discussed. Array performance measurements show that the array had a center frequency and fractional bandwidth (-6 dB) of 59.1 MHz and 29.4%, respectively. Insertion loss and adjacent element crosstalk at the center frequency were -41.0 and -23.7 dB, respectively. A B-mode image of a tungsten wire target phantom was captured using a synthetic aperture imaging system and the imaging test results demonstrate axial and lateral resolutions of 33.2 and 115.6 μm, respectively.