... Abnormalities of blood coagulation cause serious pathological complications. ... However in a number of pathologies parameters of blood coagula-tion system (BCS) can change significantly within an hour or even faster. ... It is understood that registration of yet reversible early stages of coagulation processes is considered as the most important. ... We discovered that processes of formation of microagregates at early stages of blood coagulation are accompanied by acoustic contrast. ...