Dual-concentric transducer with phase apodization for wide depth of field of high-frequency ultrasound imaging

In general, the length of the depth of field (DOF) is related to the quality of ultrasound B-mode image because the high-performance focusing can be accomplished within the DOF. Typically, under the fixed frequency and aperture size, the length of the DOF can be extended by increasing the focal depth while the intensity at focal point is reduced. This phenomenon is more severe at high frequency ultrasound imaging (HFUI) due to a short wavelength. In this study, we present a dual-concentric transducer combined with phase apodization resulting in the extended DOF maintaining intensity within the DOF range. The performance of the proposed method was numerically demonstrated by Field-II program based on 40 MHz point target and cyst imaging.