Elastic modulus measurements of human liver and correlation with pathology.
Viral hepatitis causes fibrosis in the liver and may change mechanical properties of the liver. To evaluate the impact of fibrosis on elastic properties of human liver and to investigate potential benefits of ultrasonic elasticity imaging, 19 fresh human liver samples and 1 hepatic tumor (focal nodular hyperplasia) sample obtained during operations were studied. Simple 1-D estimates based on the cyclic compression-relaxation method were performed. Elastic modulus values were derived from the predetermined strain (controlled by a step motor system) and the stress values (measured by an electronic balance). Each specimen subsequently received histologic examination and a grade of liver fibrosis was scored from 0 to 5. Results show that the elastic modulus values were on the order of several hundreds to thousands of Pascals. The elastic modulus generally increased with the fibrosis grade, although some discrepancies existed at the middle grades of fibrosis (scores 1 to 3). The correlation between the fibrosis score and the elastic modulus was significant (p < 0.01) based on the statistical analysis using the Pearson correlation method. In addition, the relation between the elastic modulus and the fibrosis grade generally exhibited a quadratic trend. It was concluded that severity of fibrosis had a good correlation with stiffness of the liver. Results also indicated that the elasticity imaging of the liver may provide significant clinical values if the elastic modulus can be accurately measured.
Yeh
Wen-Chun
WC
Department of Electrical Engineering, National Taiwan University, No. 1 Sec. 4, Roosevelt Road, Taipei, Taiwan 106.
Li
Pai-Chi
PC
Jeng
Yung-Ming
YM
Hsu
Hey-Chi
HC
Kuo
Po-Ling
PL
Li
Meng-Lin
ML
Yang
Pei-Ming
PM
Lee
Po-Huang
PH
D004548:Elasticity; D005260:Female; D006801:Humans; D007223:Infant; D008099:Liver / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography / Q000379:methods