Factors influencing the success rate and stability of transient elastography for liver fibrosis evaluation

Objective To investigate the factors influencing the success rate and stability of transient elastography(FibroScan R )for assessment of liver fibrosis. Methods Liver stiffness was assessed using transient elastography in totally 637 subjects including healthy subjects,asymptomatic hepatitis B virus (HBV) carriers,patients with chronic hepatitis B and patients with HBV-related cirrhosis. Of these subjects,302 received 2 examinations and totalling 939 examinations were perfromed. In each case,one operator performed 2 consecutive series of 10 validated measurements,or 2 operators performed a series of 10 validated measurements. The factors including dender,age,body mass index (BMI) and the state of diseases were analyzed for their association with the success of the examination. Intraclass correlation coefficient (ICC) was used to evaluate the reproducibility of the operation. Results Failure of the measurement occurred in 14 cases (2.2%),which was not associated with the age of the subjects and the state of diseases. The success rate of measurement decreased as the BMI increased (t=3.112,P=0.002),and was lower in female subjects (t=-2.193,P=0.029). The intra-and inter-operator stability of liver stiffness measurement was satisfactory,with ICC of 0.970 and 0.847,respectively. But for healthy subjects and asymptmatic HBV carriers,the stability was lower,with ICC of 0.736 and 0.639,respectively. Liver stiffness in patients with liver cirrhosis was positively correlated to complications and Child-Turcotte-Pugh (CTP) score. Conclusions Liver stiffness measurement has high stability with FibroScan R,and high BMI could lower success rate of the measurement. Liver stiffness as measured by FibroScan R allows prediction of the liver function and presence of complications in patients with liver cirrhosis.