Published online Nov 6, 2019. doi: 10.12998/wjcc.v7.i21.3463
Peer-review started: June 18, 2019
First decision: August 1, 2019
Revised: September 25, 2019
Accepted: October 15, 2019
Article in press: October 15, 2019
Published online: November 6, 2019
Processing time: 145 Days and 21.3 Hours
Non-invasive assessment of liver stiffness in children with chronic liver disease plays a critical role in clinical evaluation of liver fibrosis. Virtual touch imaging quantification (VTIQ) based on acoustic radiation force impulse imaging has been developed as a latest and noninvasive method for assessing liver stiffness in children.
Given the diversity of children in all aspects, a normal range of liver stiffness measurements must be established in children to differentiate the normal liver from abnormalities.
To determine the standard shear wave velocity (SWV) values in healthy children, and to identify possible factors that might influence the VTIQ measurement.
We conducted a prospective study. After exclusion, a total of 202 children between 1 mo and 15 years old were included in this study. None of them had any liver or systematic diseases. All children had a normal ultrasound scan and normal body mass index (BMI) range. The subjects were divided into four age and BMI groups. The effects of gender, age, liver lobe, measurement depth, and BMI on liver elasticity were investigated.
A significant correlation was found between age and SWV values. At measurement depths of 1.5 cm and 2.0 cm in the left lobe, there were significant differences among the four age groups. Negative correlations were found between the measurement depth and SWV values. Gender, liver lobe, and BMI showed no significant effect on the SWV values. Age and BMI may influence the quality of the elastogram.
As a recently developed noninvasive technique, VTIQ is feasible for physicians to measure liver stiffness in children. Lower SWV values are expected in younger children, and at a deeper measurement depth. Liver elasticity is not affected by gender, BMI, and the location of measurement. Therefore, when available, the VTIQ measurement at deep regions in the right lobe of the liver is preferably suggested.
The results of this study provide a range of normal reference values for measuring the liver elasticity in normal children. In the future, more subjects should be incorporated to further confirm the results of this study, and the consistency between observers needs to be evaluated so that VTIQ technology can be better applied to clinical practice. More importantly, with the reliable normal reference value, this noninvasive method can widely be used to detect and evaluate liver fibrosis in children.