Focal and diffuse liver disease studied by quantitative microstructural sonography.

Abstract

Quantitative microstructural sonography differs from conventional sonography in several ways. The frequency as well as the amplitude of echoes is recorded and assessed using spectral analysis techniques. The effects of diffraction of the ultrasound beam are calibrated, as are the transfer characteristics of the system. Studies of patients with alcoholic liver disease revealed significantly increased attenuation, heterogeneity of scatterers, and local scattering strength in those with severe disease; in contrast, patients with mild cirrhosis exhibited decreased local scattering strength compared to normal individuals. Using retrospective three-parameter discriminant analysis, 23 out of 24 patients were successfully categorized, suggesting that the parameters used were capable of measuring microstructural changes associated with these disease states. Parameters varied widely among 6 types of hepatic tumors, suggesting that this method may offer promise in distinguishing tumors from normal cases and alcoholic liver disease as well as from each other. Further applications and evaluation of this method appear justified.

Ultrasonography and Computed Tomography in Diffuse Liver Disease with Cholestasis

“…Recently, using a short-focused 5 MHz small parts probe, liver surface irregularities have been detected as a new objective US sign for diagnosing hepatic cirrhosis (2). Ultrasonic parameters provided for tissue characterization may also be helpful in differentiating between benign and malignant diffuse parenchymal liver disease (14).…”

<title>Current directions in automated medical image analysis</title>

“…Human observer studies [9,10,1 1] have shown that even trained radiologists perform poorly at the task of discriminating difftise diseases using only B-mode ultrasound images. This has lead to the use of quantitative analysis of the backscattered radio-frequency (RE) ultrasound signal as a means of detecting diffuse diseases in the liver [1 [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], kidney [17], spleen [12], and prostate [18,19] A model of tissue scattering developed by Wagner et al [20] consists of three distinct types of scatterers. A large number of randomly located small scatterers per resolution cell results in a diffuse scattering component of the backscattered signal.…”

Ultrasonic tissue characterization via 2‐D spectrum analysis: Theory and in vitro measurements

“…14 This technique utilizes the radio-frequency (rf) echo signals measured directly at conventional clinical ultrasound probes. It has proven to be useful in the diagnosis of diseases in various organs, ranging from eye, 15,16 breast, 17,18 prostate, 19 kidney and liver, 20,21 to plaque 22,23 and lymph nodes. 24 We have extended this 1-D technique to 2-D using the same clinical data to more fully characterize tissue microstructures in terms of their physical properties.…”