In Vitro Study on Assessment of Blood Coagulation and Clot Formation Using Doppler Ultrasound

A 10 MHz pulsed Doppler ultrasound was applied to measure both Doppler power and Doppler velocity from stirred porcine blood of various hematocrits for assessing variations in blood properties during blood coagulation and clot formation. For each measurement, blood was recalcified by adding calcium chloride solution. Results obtained from original blood at hematocrits of 25, 35, 45, and 55% showed that the mean Doppler power and Doppler velocity were respectively equal to 40.2, 38.5, 38.1, and 37.6 dB, and 24.6, 21.4, 20.0, and 19.6 cm/s. The variations in blood properties during blood coagulation caused Doppler power and velocity to fluctuate markedly. As the clot was formed, Doppler power was increased by approximately 5.5 dB and velocity was decreased to approximately 5.2 cm/s. These studies validated the suggestion that Doppler ultrasound is a feasible and sensitive means to quantify blood properties during blood coagulation and clot formation.