Suzuki K, Hayashi N, Sasaki Y, Tanaka Y, Kono M, Imai Y, Fusamoto H, Kamada T
First Department of Medicine, Osaka University Medical School, Japan.
Front Med Biol Eng. 1991;3(4):269-81.
To evaluate the morphological changes in chronic liver disease non-invasively we used the frequency-domain analysis of ultrasound. We assumed that liver tissue is a collection of semi-regularly arrayed small scatterers of ultrasound. We applied cepstral analysis to ultrasonic waveforms and evaluated the periodicity of scalloping of the power spectrum, caused by an interference effect among liver scatterers of a given spacing. In a phantom experiment, we could correctly measure the space among scatterers of a phantom consisting of a regularly spaced distribution of nylon filaments. In an experiment involving a freshly excised porcine liver, the distribution of the space among scatterers (SAS) determined on cepstral analysis reflected the size distribution of the hepatic lobules. In a human study, two statistical parameters, mode and kurtosis, were determined from the distribution of the SAS for each patient. In a previous study, we collected ultrasonic data during peritoneoscopy with a 10 MHz transducer directly contacting the liver and showed that we could evaluate morphological changes in chronic liver disease using cepstral analysis. In the present study, we obtained data in two ways: with a 3.5 MHz transducer through the abdominal wall and with a 10 MHz transducer directly contacting the liver during peritoneoscopy. The mode and kurtosis of the SAS obtained with the 3.5 MHz transducer were both well correlated with the mode and kurtosis of the SAS obtained with the 10 MHz transducer. These results suggest that we can evaluate morphological changes in chronic liver disease non-invasively.
为了无创评估慢性肝病的形态学变化，我们采用了超声的频域分析。我们假定肝组织是超声半规则排列的小散射体的集合。我们将倒谱分析应用于超声波形，并评估由给定间距的肝散射体之间的干涉效应引起的功率谱扇贝形的周期性。在一个体模实验中，我们能够正确测量由规则间隔分布的尼龙丝组成的体模中散射体之间的间距。在一项涉及新鲜切除猪肝的实验中，通过倒谱分析确定的散射体之间间距（SAS）的分布反映了肝小叶的大小分布。在一项人体研究中，为每位患者从SAS分布中确定了两个统计参数，众数和峰度。在之前的一项研究中，我们在腹腔镜检查期间使用10MHz换能器直接接触肝脏收集超声数据，并表明我们可以使用倒谱分析评估慢性肝病的形态学变化。在本研究中，我们通过两种方式获取数据：使用3.5MHz换能器经腹壁获取，以及在腹腔镜检查期间使用10MHz换能器直接接触肝脏获取。用3.5MHz换能器获得的SAS的众数和峰度均与用10MHz换能器获得的SAS的众数和峰度高度相关。这些结果表明我们可以无创评估慢性肝病的形态学变化。
