High frequency ultrasound characterization of the coagulation process of whole blood

This study was designed to characterize the blood clotting process in vitro by following changes in its acoustic properties. High frequency (from 20 to 45 MHz) ultrasound parameters were measured both in double transmission (sound velocity) and backscattering (backscatter coefficient, integrated backscatter coefficient and effective scatterer size) mode. Whole blood samples were collected from healthy volunteers. The protocol to initiate the coagulation process is describe. During the blood clotting process (two hours' observation), acoustic parameters were measured with 15 seconds time resolution for the transmission parameters and 1 minute for the backscattering parameters. The results clearly showed that changes in several acoustic parameters are able to identify several stages in the in vitro blood clotting process, in particular, red blood cell aggregation and blood solidification.