Abstract / Summary
Strain elastography is often limited by its relative nature and failure to capture temporal changes. This study aimed to establish a novel quantitative strain index (Q-SI) integrating spatiotemporal analysis and evaluate its utility for assessing liver fibrosis. This prospective study included patients with chronic liver disease (CLD) or chronic heart failure (CHF) between June 2020 and March 2022. The Q-SI was established by applying Q-Analysis to spatiotemporal strain map data, averaging values over 5–10 cardiac cycles. Correlations with two-dimensional shear wave elastography (2D-SWE) and vibration-controlled transient elastography (VCTE) were assessed. Diagnostic performance in histological fibrosis staging was compared using areas under the curve (AUC). A total of 201 participants (194 CLD, 7 CHF) were evaluated. In the CLD cohort, Q-SI showed a significant negative correlation with 2D-SWE ( r = − 0.51, P <0.001) and VCTE ( r = − 0.53, P <0.001). Q-SI also decreased significantly with advancing histological fibrosis stage. Diagnostic accuracy (AUC: ≥ F2, 0.74; ≥ F3, 0.73; F4, 0.84) was comparable to that of 2D-SWE (0.73, 0.76, and 0.76) and that of VCTE (0.77, 0.83, and 0.88). Unlike 2D-SWE and VCTE, Q-SI was not affected by high alanine aminotransferase levels. In the CHF cohort, the Q-SI correlated strongly with right atrial reservoir strain ( r = 0.90, P < 0.01), an indicator of right atrial pressure, but not with left ventricular ejection fraction. Q-SI provides a strain-based assessment of liver fibrosis comparable to that of shear wave-based techniques, with potential resilience to inflammation and independence from left ventricular function.