Application of a quality threshold to improve liver shear wave elastography measurements in free-breathing pediatric patients
- Author:
Jisoo KIM
1
;
Naohisa KAMIYAMA
;
Shunichiro TANIGAWA
;
Haesung YOON
;
Hyun Ji LIM
;
Mi-Jung LEE
Author Information
- Publication Type:1
- From: Ultrasonography 2024;43(5):354-363
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:This study assessed the benefits of quality threshold (QT) implementation for liver shear wave elastography (SWE) in children during free breathing.
Methods:The QT, which adjusts the SWE map display based on shear wave quality, was set at 55%. Phantom measurements (PMs) were taken with a fixed probe using QT (termed PM-1); a moving probe without QT (PM-2); and a moving probe with QT (PM-3). Each measurement was subjected to random samplings of various sizes. Clinical measurements (CMs) were obtained from children with biliary atresia using following protocols: CM-1, manually defined regions of interest (ROIs); CM-2, default ROIs without QT; and CM-3, default ROIs with QT. Elasticity measurements were compared across fibrosis grades, and color patterns on the SWE maps were analyzed.
Results:In the phantom experiments, the moving probe produced lower elasticity measurements; this difference decreased upon QT application. With the moving probe, random sampling indicated fewer interquartile range-to-median ratios exceeding 30% upon QT application (4% vs. 14% when five values were sampled, P=0.004). In clinical experiments, QT improved the differentiation of fibrosis grade in patients over 5 years old, with a significant difference between moderate and severe fibrosis (P=0.004). Elasticity variability was positively correlated with fibrosis grade (τ=0.376, P<0.001). Certain apparent errors, termed artificial stripe patterns, were not eliminated by QT.
Conclusion:Applying QT to exclude low-quality pixels can minimize measurement error and improve differentiation of liver fibrosis grades. The presence of an artificial stripe pattern on the SWE map may indicate images requiring exclusion.
