Effects of body position, probe position and direction on visual transient elastography for liver stiffness mesurement

Objective To explore the influencing factors of visual transient elastography (ViTE) for liver stiffness measurement (LSM) among healthy population. Methods The Mindray's Resona6 ViTE technique was used to randomly measure the liver stiffness of healthy adults. The impacts of body position, probe position and direction on LSM were analyzed. Furthermore, we assessed the impacts of age, sex, height, weight, BMI, and subcutaneous fat thickness on LSM. Results The LSM values from the supine and the left decubitus position were (4.99±1.22) kPa and (6.56±3.06) kPa respectively, and the difference was statistically significant. The LSM values obtained from the right intercostal space and the right inferior margin of costal arch were (4.99±1.22) kPa and (4.43±1.46) kPa respectively, and the difference was statistically significant. The LSM values obtained when the probe was perpendicular to the chest wall, at an angle of 15° to the vertical direction of the chest wall, and at an angle of 30° to the vertical direction of the chest wall were (4.99±1.22) kPa, (5.20±1.53) kPa, (6.04±2.41) kPa respectively, and the difference was also statistically significant. This study also found no significant effects of age, sex, height, weight, BMI, and subcutaneous fat thickness on LSM. Moreover, the detection success rate of the right lobe of liver was significantly higher than that of the left lobe. Conclusions During liver stiffness measurement by ViTE, it is necessary to consider the influence of subject's body position, probe direction and position on the LSM value.