Characterization of tissue microstructure using ultrasonic backscatter: Theory and technique for optimization using a Gaussian form factor
Characterization of tissue microstructure using ultrasonic backscatter: Theory and technique for optimization using a Gaussian form factor
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DOI：
10.1121/1.1501278
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发表时间：
2002-09-01
影响因子：
2.4
通讯作者：
Zachary, JF
中科院分区：
文献类型：
--
作者：
Oelze, ML;Zachary, JF
假设通过超声背向散射表征组织微观结构有助于检测和分类病变组织。从组织背散射的射频信号可以根据组织中散射体的假定形状、大小和分布来建模。射频后向散射信号的功率谱描述了散射体的频率依赖性。在4 ~ 12 MHz的频率范围内，对大鼠自发性乳腺肿瘤的超声背向散射进行了实验测量。从大鼠肿瘤测得的功率谱相比，来自一个3D空间自相关函数假设高斯分布的理论功率谱。平均散射体直径和声集中的独立值通过用最佳拟合线近似测量的功率谱而获得。增强的B模式图像是由大鼠肿瘤和周围组织与叠加的感兴趣的区域量化估计的平均散射体的大小和声浓度。散射特性估计内的肿瘤和周围组织被证明是不同的。总体而言，估计显示与肿瘤外的组织相比，肿瘤内的平均散射体直径增加了44.8%。除一只大鼠外，肿瘤内散射体平均声浓度的所有估计值均小于肿瘤外。(C)2002年美国声学学会。
Characterization of tissue microstructure through ultrasonic backscatter is hypothesized to aid in detection and classification of diseased tissues. Radio frequency signals backscattered from tissues can be modeled according to the assumed shape, size, and distribution of scatterers in tissues. Power spectra of rf backscattered signals describe the frequency dependence of scatterers. Experimental measurements of ultrasonic backscatter from spontaneous mammary tumors in rats are obtained over the frequency range of 4 to 12 MHz. The power spectra measured from rat tumors are compared to theoretical power spectra derived from a 3D spatial autocorrelation function assuming a Gaussian distribution. Independent values of average scatterer diameter and acoustic concentration are obtained by approximating the measured power spectrum with a best-fit line. Enhanced B-mode images are made of the rat tumors and surrounding tissues with superimposed regions of interest quantified by estimated average scatterer sizes and acoustic concentrations. Scattering properties estimated inside the tumors and in surrounding tissues are shown to be distinct. Overall, estimates showed a 44.8% increase of average scatterer diameter inside the tumor as compared to tissues outside the tumor. With the exception of one rat, all estimates of the scatterers' average acoustic concentration inside the tumor were less than outside the tumors. (C) 2002 Acoustical Society of America.