A Preliminary Study On Sound Velocity Tissue Quantification In Diagnosis Of Diffuse Liver Disease

Objective1. To establish the measuring methods and relevant influencing factors of liver zone speed index (ZSI) by sound velocity tissue quantification (STQ) technology in healthy subjects.2. To investigate the clinical application value of ZSI in the differential diagnosis of diffuse liver disease by measurement of the ZSI value of22patients with single fatty liver,21cases of diabetes mellitus,25cases of diabetes mellitus with fatty liver,and chronic hepatitis B cirrhosis in29cases using sound velocity tissue quantification (STQ) technology.Methods1. Liver ZSI were obtained in49healthy volunteers using STQ technique with ZONARE zone ultra system. In the first15subjects, ZSI were acquired at four positions (superficial and deep parts of right hepatic lobe, superficial and deep parts of left hepatic lobe). Then the achievement rate in different position of liver was calculated to select the suitable measuring position. The reproducibility was analyzed with intraclass correlation coefficient (ICC). The last34healthy subjects received ZSI measurements in the appropriate position only. The reference value of ZSI was calculated using x±1.96s. Relation between age, gender, body mass index and ZSI were analyzed.2. STQ was performed in22patients with simple fatty liver (SFL),21with diabetes mellitus (DM),25with diabetes mellitus complicated with fatty liver (DM+FL),29with chronic hepatitis B cirrhosis (HC)and49normal volunteers as control group (NC). The value of ZSI was tested in1cm below the capsule of right hepatic lobe. Analysis of variance was adopted to compare ZSI values of each group, and cutoff values of each group were obtained by ROC curves, meanwhile, the coefficient of variation of ZSI D-value obtained by two operators was calculated..Results1. It was stable to measure values of ZSI with STQ technique. Satisfied ZSI values were obtained in the right hepatic lobe in49normal subjects whereas not obtained in the left hepatic lobe in11subjects, showing a significantly higher achievement rate of right hepatic lobe than left lobe (χ2=16.18, P<0.005) by chi-square test. There was no significant difference of ZSI value between male and female groups. There was no significant correlation between age and values of ZSI while a significant negative correlation was found between body mass index (BMI) and values of ZSI (r=-0.63, P=0.000). The reference value of body mass index between18.5-23.9kg/m2was5.67～36.29m/s.2. Compared with the normal control group, the mean of ZSI was significantly lower in SFL group (5.8±18.5vs21.0±7.8,<0.05,), while that of ZSI was significantly higher in HC group and DM+FL group (29.4±13.2,32.6±18.3vs21.0±7.8, P<0.05). Moreover, the mean of ZSI in DM+FL group was higher than that of ZSI in HC group.The coefficient of variation of ZSI D-value between the two operators was0.186.Conclusions1. There are no significant difference between the ZSI value of the right hepatic lobe and that of the left hepatic lobe. Achievement rate of obtaining satisfied ZSI of the right hepatic lobe was significantly higher than that of the left hepatic lobe.2. STQ imaging does not depend on the operator and can be used accurately in quantitative evaluation of liver tissue hardness by ultrasonic velocity change in the tissue.3. STQ imaging presented obviously quantitative differences trend in the differential diagnosis of tissue elasticity of HC, DM+FL and SFL. With noninvasive, convenient and objective characteristics, STQ imaging may be a new promising method for assessment of liver elasticity quantitatively.