Use of Sound Touch Elastography and Sound Touch Quantification for the Noninvasive Evaluation of Portal Hypertension in a Rat Model

Abstract

Objectives In this study, we used the recently developed ultrasound elastography techniques sound touch elastography (STE) and sound touch quantification (STQ) to quantify portal hypertension (PHT) severity in a rat model of carbon tetrachloride (CCl4)‐induced cirrhotic PHT. Methods In total, 60 rats were used. Various degrees of PHT were established. Liver and spleen stiffness were measured by STE (L‐STE and S‐STE, respectively) and STQ (L‐STQ and S‐STQ, respectively). We measured portal pressure (PP) after ultrasonographic examination. The performance of the STE and STQ parameters in the identification of PHT was evaluated using receiver operating characteristic (ROC) analyses. Results Liver and spleen stiffness measurements obtained with STE and STQ correlated positively with the PP (r = 0.566–0.882, all P < .001). The areas under ROC curves for L‐STE, S‐STE, L‐STQ, and S‐STQ values were 0.931 (95% confidence interval [CI], 0.847–1.000), 0.982 (95% CI, 0.956–1.000), 0.796 (95% CI, 0.680–0.912), and 0.925 (95% CI, 0.858–0.993), respectively, for PP ≥5 mmHg; 0.937 (95% CI, 0.865–1.000), 0.938 (95% CI, 0.864–1.000), 0.967 (95% CI, 0.923–1.000), and 0.960 (95% CI, 0.897–1.000), respectively, for PP ≥10 mmHg; and 0.954 (95% CI, 0.897–1.000), 0.790 (95% CI, 0.652–0.928), 0.808 (95% CI, 0.680–0.935), and 0.740 (95% CI, 0.595–0.885), respectively, for PP ≥12 mmHg. Conclusions STE and STQ are reliable noninvasive tools for the assessment of PHT severity, especially for PP ≥10 mmHg, in a rat model of CCl4‐induced cirrhotic PHT.