Summary
Fibrinogen clotting has been studied by means of the spin echo technique. Magnetic
transversal T2 and longitudinal T1 relaxation times were measured during fibrin formation.
Human fibrinogen was clotted by means of thrombin, papain and reptilase, which were
used in three different concentrations.
The time relations of T2 in the studied system reflect, among others, limitation of freedom of movement of
molecules of fibrinogen in the process of formation of the fibrin clot. Distinct differences
were found related to the concentration and type of enzyme used to clot fibrinogen.
Comparison of the results obtained by the spin echo technique with results of measurements
of optical density and thromboelastographic measurements led to the conclusion that
the study of relaxation times T1 and T2 provides new information relative to fibrin formation, mainly with reference to increasing
rigidity of the fibrin network and binding of water in it. This information is significant
in that it determines quantitatively the degree of limitation of movement of molecules
in the fibrin clot and characterizes its functional value. This conclusion was confirmed
by the thromboelastographic studies, which allowed correlation of the changes in T2 time with mechanical properties of the clot.
