Quantitative Compression Ultrasound via a Force-Area Digital Twin for Mechanistic Assessment of Venous Thrombosis

Conventional compression ultrasound (CUS) is qualitative and operator-dependent. This work investigates whether probe compression force combined with lumen shape provides mechanistic information beyond the binary compressibility used in clinical practice. This study establishes a mechanistically grounded framework for quantitative CUS by simultaneously measuring probe compression force and vein deformation during ultrasound imaging and investigates how thrombus mechanics shape the resulting force-deformation response to distinguish healthy and thrombotic vein states.

Compression force and internal jugular vein (IJV) cross-sectional area were recorded during CUS in nine healthy subjects to establish a healthy reference response. Two quantitative indicators were derived from the compression response: the loading branch force-area slope and an aspect ratio-based deformation metric. A representative finite-element digital twin of the IJV region was constructed using cohort mean anatomical landmarks and physiological literature data and tuned to reproduce experimentally observed healthy compression behaviour. Simulated thrombotic configurations were then introduced to evaluate their influence on force-area and force-shape responses.

Simulated thrombotic configurations produced systematically steeper force-area responses and reduced lumen collapse compared with the healthy reference. Partial occlusions generated intermediate and morphologically distinct deformation patterns. The simulated dimensional force-area slope remained of the same order of magnitude as the experimental value. The normalised force-area slope agreed closely between the simulation and the experimental cohort, indicating that the model captures the underlying shape of the compression response.

This study establishes a mechanistic proof of concept for quantitative CUS and demonstrates in silico separability between healthy and thrombotic compression responses. By linking measurable compression signatures to the underlying thrombus mechanics, this work moves quantitative CUS from an empirical observation towards a physics-informed biomechanical biomarker. Clinical validation in subjects with confirmed thrombosis is still required.