Evaluation of structural change in diffuse liver disease with frequency domain analysis of ultrasound

✍ Scribed by Kunio Suzuki; Norio Hayashi; Yutaka Sasaki; Michikazu Kono; Akinori Kasahara; Yutaka Imai; Hideyuki Fusamoto; Takenobu Kamada

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 647 KB
• Volume: 17
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840170616

✦ Synopsis

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 = ll), 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. (HEPATOLOGY 1993;17:1041-1046.) Gray-scale ultrasonography is useful in the diagnosis of focal lesions and bile duct obstruction in the liver. However, diffuse parenchymal diseases of the liver such as cirrhosis and fatty infiltration are difficult to diagnose reliably on the basis of the B-mode image alone. For example, it has been reported that patients with fatty liver cannot be reliably distinguished from patients with cirrhosis (1, 2). In addition, B-mode ultrasonography