Estimation of the Scatterer Distribution for Quantitative Diagnosis using Ultrasonic Image

在超声成像系统获得的肝脏的B型图像中，斑点图案随着疾病的进展而变化，如肝硬变。人类的肝脏由被称为肝小叶的小六角形结构组成。我们提出了一种考虑肝脏小叶结构的散射体在肝组织上分布变化的建模技术，以获得连续阶段的肝硬变图像。该建模技术可以有效地分析生物组织特征变化与B超图像变化在肝硬变发展过程中的关系。然后，介绍了肝脏回波包络的统计特征，以及利用恒虚警率(CFAR)处理从正常肝脏图像和肝硬变图像中提取散射体分布信息的方法。我们分析了提取的散射体分布与肝硬变分期的关系。处理信号幅度大于阈值的区域占整个处理图像区域的比例与肝硬变的分期有定量的关系。结果表明，该方法对肝硬变的定量诊断是有效的。

In the B-mode image of the liver obtained by an ultrasonic imaging system, the speckled pattern changes with the progression of the disease such as liver cirrhosis. The human liver is composed of small hexagonal structures known as the liver lobules. We propose a modeling technique for the change of the scatterer distribution on liver tissue considering the liver lobule structure to obtain cirrhotic liver images of the continuous stage. The proposed modeling technique is valid for analyzing the relationship between the change of characteristics of biological tissue and change of B-mode image on the progression of liver cirrhosis. Then, we present the statistical characteristics of the echo envelope of the liver, and the technique to extract information of the scatterer distribution from the normal and cirrhotic liver images using constant false alarm rate (CFAR) processing. We analyze the relationship between the extracted scatterer distribution and the stage of liver cirrhosis. The ratio of the area in which the amplitude of the processing signal is more than the threshold to the entire processed image area is related quantitatively to the stage of liver cirrhosis. It is found that the proposed technique is valid for the quantitative diagnosis of liver cirrhosis.