2021 Volume 46 Issue 2 Pages 117-125
Objective: The difference in results from shear wave elastography (SWE) could be caused by variations in degrees of measurements and procedure conditions. We aimed to improve the reliability and precision of SWE by defining the optimal measurement conditions and assessing the reproducibility among evaluators.
Subjects and Methods: Five sonographers measured shear wave velocity (SWV; m/s) in six persons without liver disease (mean age, 46.5±15.4 years; male, n＝2; female, n＝4) by ultrasound using an Aplio300 with a PVT-375BT probe (Canon Medical Systems). We calculated inter- and intraevaluator variations in the measured values and compared these values with set scores of 1 or 4 on the region of interest (ROI), in the supine position, with a slightly lateral decubitus position, and number of measurements. We used t-tests and intraclass correlation coefficients (ICCs) to statistically analyze the data.
Results: In four of the five sonographers, the ICC (1,1 and 3,5) of intra- and interevaluator variability, respectively, was ＞0.7. There was a significant difference in the data from two of the six evaluees and from one of the five evaluators. The position of the evaluee during the procedure did not differ significantly. Single measurements and the average of three measurements differed significantly, whereas the average of three, six, nine, and 12 measurements did not.
Discussion: A high coefficient of variation for liver sections under different test conditions or in selecting the ROI contributed to variations in SWV.
Conclusions: Results were more accurate for persons without liver disease under uniform test conditions, with single measurements, in a supine posture, and when three measurements were averaged.
