Wang Zhuochen, Li Sibo, Czernuszewicz Tomasz J, Gallippi Caterina M, Liu Ruibin, Geng Xuecang, Jiang Xiaoning
IEEE Trans Ultrason Ferroelectr Freq Control. 2016 Feb;63(2):266-74. doi: 10.1109/TUFFC.2015.2506000. Epub 2015 Dec 4.
Ultrasound imaging with high resolution and large penetration depth has been increasingly adopted in medical diagnosis, surgery guidance, and treatment assessment. Conventional ultrasound works at a particular frequency, with a [Formula: see text] fractional bandwidth of [Formula: see text], limiting the imaging resolution or depth of field. In this paper, a bifrequency colinear array with resonant frequencies of 8 and 20 MHz was investigated to meet the requirements of resolution and penetration depth for a broad range of ultrasound imaging applications. Specifically, a 32-element bifrequency colinear array was designed and fabricated, followed by element characterization and real-time sectorial scan (S-scan) phantom imaging using a Verasonics system. The bifrequency colinear array was tested in four different modes by switching between low and high frequencies on transmit and receive. The four modes included the following: 1) transmit low, receive low; 2) transmit low, receive high; 3) transmit high, receive low; and 4) transmit high, receive high. After testing, the axial and lateral resolutions of all modes were calculated and compared. The results of this study suggest that bifrequency colinear arrays are potential aids for wideband fundamental imaging and harmonic/subharmonic imaging.
具有高分辨率和大穿透深度的超声成像已越来越多地应用于医学诊断、手术引导和治疗评估。传统超声在特定频率下工作，分数带宽为[公式：见原文]，限制了成像分辨率或景深。本文研究了一种谐振频率为8和20 MHz的双频共线阵列，以满足广泛超声成像应用对分辨率和穿透深度的要求。具体而言，设计并制作了一个32阵元的双频共线阵列，随后使用Verasonics系统对其进行了阵元特性表征和实时扇形扫描（S扫描）体模成像。通过在发射和接收时在低频和高频之间切换，对双频共线阵列进行了四种不同模式的测试。这四种模式包括：1）发射低频，接收低频；2）发射低频，接收高频；3）发射高频，接收低频；4）发射高频，接收高频。测试后，计算并比较了所有模式的轴向和横向分辨率。本研究结果表明，双频共线阵列是宽带基波成像和谐波/次谐波成像的潜在辅助工具。
