Quantitative US attenuation in normal liver and in patients with diffuse liver disease: importance of fat.

Abstract

Two methods are used to estimate ultrasound attenuation in liver. These were based on amplitude change and frequency change as a result of depth dependent attenuation. Evaluation of the two methods against a family of calibrated phantoms yielded correlation coefficients of 0.98 and 0.99, respectively. Liver attenuation in 26 control subjects was 0.50 and 0.52 dB/MHz/cm, respectively. Liver attenuation was estimated in 50 patients who later underwent liver biopsy. Comparison with quantitative histologic results showed that the presence of fat alone accounted for the increased attenuation associated with cirrhosis. Similar high attenuation values were found in patients with fatty infiltration. Fibrosis alone did not result in elevated liver attenuation. Cirrhotics without fatty infiltration had attenuation similar to that of the controls. Mechanisms of action are discussed.

Comparative evaluation of fatty infiltration of the liver in dairy cattle by using blood and serum analysis, ultrasonography, and digital analysis

“…Also in humans, ultrasonography was found to be more accurate than biochemical analysis in the diagnosis of various liver disorders (11). With ultrasonography, the accuracy, sensitivity, and specificity obtained for the diagnosis of fatty infiltration were 85%, 100%, and 56%, respectively (10).…”

Comparison of sonograms and liver histologic findings in patients with chronic hepatitis C virus infection.

“…A liver was considered inflammatory if echogenic portal triads were observed in a hypoechoic liver or preservation of portal triads was noted in a background of fatty infiltration. 5,8 If any features of cirrhosis were present, including an irregular contour or nodularity, the liver disease was graded as severe (3) fibrosis. Grading was otherwise done subjectively for degree of severity of the various ultrasonographic patterns.…”

“…2 Gray scale ultrasonography has been reported to detect histologic features of chronic liver disease. [3][4][5][6][7][8][9][10] We compared retrospectively the gray scale liver images and histologic results in hepatitis C patients evaluated with sonographically guided liver biopsy to see if any correlation existed between sonographic and biopsy findings. If a positive correlation did exist, ultrasonography could be an important costeffective means of monitoring the disease in these patients.…”

Tissue mimicking materials for a multi‐imaging modality prostate phantom

“…[1][2][3][4][5][6][7][8] TM materials for use in ultrasound should have the same ranges of propagation speeds, attenuation coefficients, and backscatter coefficients as the mimicked soft tissue type. Ultrasound propagation speeds and attenuation values for human skeletal muscle and subcutaneous abdominal fat and breast fat are shown in Tables II [9][10][11][12][13] and III, [14][15][16][17][18] respectively. Data for prostate tissue could not be found in the literature, so values for the liver gland are given as possibly relevant.…”