Analysis of blood clot formation with transient elastography: similarity with sol-gel transition in agar-gelatin phantoms

Blood coagulation plays an important role in many cardiovascular diseases like atherosclerosis, heart stroke and deep vein thrombosis. The characterization of blood clot mechanical properties is fundamental in determining the appropriate treatment and for understanding the etiology of these pathologies. Intuitively, the blood coagulation can be considered as a transition from a liquid to a solid state. This behavior seems to be very close to the sol-gel transition in polymer mixture. In this paper, the validity of transient elastography to follow-up the sol-gel transition of an agar-gelatin mixture is shown. The results obtained are in good agreement with the literature and theoretical predictions. Experiments were also performed on blood pig samples in vitro. The analogy between the viscoelastic behavior of the polymer mixture and that of blood clot formation as a function of time is discussed and shown to be similar.