Suzuki K, Hayashi N, Sasaki Y, Kono M, Kasahara A, Imai Y, Fusamoto H, Kamada T
First Department of Medicine, Osaka University Medical School, Japan.
Hepatology. 1993 Jun;17(6):1041-6.
To evaluate structural changes in diffuse liver disease, frequency domain analysis was applied to ultrasonic signals from the liver. We assumed that liver tissue is a collection of semiregularly arrayed small scatterers of ultrasound. We applied cepstral analysis to the ultrasonic waveforms and evaluated the periodicity of scalloping of the power spectrum caused by an interference effect among liver scatterers of a given spacing. Patients with liver conditions involving nonspecific change (n = 6), chronic hepatitis (n = 11), cirrhosis (n = 7) or fatty liver (n = 6) were examined. One hundred ultrasonic signals were obtained noninvasively with a 3.5-MHz transducer, and the space among scatterers was calculated for each signal using cepstrum analysis. Two statistical parameters, mode and kurtosis, were determined from the distribution of the space among scatterers for each patient; these parameters were compared with the histological findings in the liver. Space among scatterers kurtosis decreased with progress of liver fibrosis, and space among scatterers mode increased in cirrhosis. Neither space among scatterers kurtosis nor space among scatterers mode was affected by pathological fat in the liver. These results suggest that we can evaluate fibrotic changes in diffuse liver disease and that we can also noninvasively discriminate diffuse fibrotic liver disease from fatty liver.
为评估弥漫性肝病的结构变化，将频域分析应用于肝脏的超声信号。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脏散射体之间的干涉效应引起的功率谱扇贝状的周期性。对患有非特异性改变（n = 6）、慢性肝炎（n = 11）、肝硬化（n = 7）或脂肪肝（n = 6）的肝病患者进行了检查。使用3.5兆赫换能器无创获取100个超声信号，并使用倒谱分析为每个信号计算散射体之间的间距。从每位患者散射体之间间距的分布确定两个统计参数，众数和峰度；将这些参数与肝脏的组织学结果进行比较。散射体之间间距的峰度随肝纤维化进展而降低，散射体之间间距的众数在肝硬化中增加。散射体之间间距的峰度和散射体之间间距的众数均不受肝脏病理性脂肪的影响。这些结果表明，我们可以评估弥漫性肝病的纤维化变化，并且还可以无创地区分弥漫性纤维化肝病和脂肪肝。
