Knipp B S, Zagzebski J A, Wilson T A, Dong F, Madsen E L
Department of Medical Physics, University of Wisconsin, Madison 53706, USA.
Ultrason Imaging. 1997 Jul;19(3):221-33. doi: 10.1177/016173469701900305.
Most methods for in vivo quantitation of ultrasound attenuation and backscatter are not available clinically because they rely upon acquiring and analyzing radio frequency (rf) echo signals. This paper describes a technique to estimate ultrasound attenuation and backscatter from B-mode image data. The video signal analysis (VSA) technique utilizes images of a reference phantom, taken using the same instrument settings used to record images from the patient or sample, to account for effects of the transducer beam, system gain and signal processing on image data. A 'gray-scale look-up table' is derived to convert image pixel value data within a region of interest to echo signal amplitudes relative to echo signals from the same depth in the reference phantom. These relative echo levels enable estimates of attenuation and backscatter in the region of interest. VSA was used to quantify acoustic properties of test phantoms using 3 different clinical scanners and various transducers. The level of agreement between results obtained with different ultrasound imaging systems was very good. VSA attenuation and backscatter levels also compare favorably with attenuation coefficients and backscatter coefficients obtained using rf analysis.
大多数用于体内超声衰减和背向散射定量分析的方法在临床上不可用，因为它们依赖于采集和分析射频（rf）回波信号。本文描述了一种从B模式图像数据估计超声衰减和背向散射的技术。视频信号分析（VSA）技术利用参考体模的图像，这些图像是使用与记录患者或样本图像相同的仪器设置拍摄的，以考虑换能器波束、系统增益和信号处理对图像数据的影响。导出一个“灰度查找表”，将感兴趣区域内的图像像素值数据转换为相对于参考体模中相同深度的回波信号的回波信号幅度。这些相对回波水平能够估计感兴趣区域内的衰减和背向散射。使用3种不同的临床扫描仪和各种换能器，VSA被用于量化测试体模的声学特性。不同超声成像系统获得的结果之间的一致性水平非常好。VSA衰减和背向散射水平也与使用rf分析获得的衰减系数和背向散射系数相比具有优势。
