Evaluation of optical coherence tomography for the measurement of the effects of activators and anticoagulants on the blood coagulation in vitro

Blood Coagulation Following an Acute Ischemic Stroke

Objective. Hemostasis is a complex physiological process that stops bleeding at the site of a vascular injury. Although the majority of vascular accidents are ischemic, the role of hypercoagulable state and stroke needs further investigation. Materials and Methods. Fresh whole blood was taken from 61 acute ischemic stroke patients and compared to 18 healthy subjects and investigated with optical coherence tomography imaging after initiating coagulation. We used an OCT1300SS system (Thorlabs) and did 3D scans. We then processed the images with ImageJ. For each image mean, integrated density, skewness and kurtosis of gray values were analyzed. Results. Mean gray value and integrated intensity of sampled data showed an intrinsic difference detected with OCT. This difference was further confirmed by the data distribution analysis. Conclusions. Results suggest, that normal blood coagulation, is not a random reaction while in the case of stroke patients, the relatively symmetrical distribution of gray values brings coagulation closer randomized process.

Effect of fibrinogen on blood coagulation detected by optical coherence tomography

Our previous work demonstrated that an optical coherence tomography (OCT) technique and the parameter 1/e light penetration depth (d1/e) were able to characterize the whole blood coagulation process in contrast to existing optical tests that are performed on plasma samples. To evaluate the feasibility of the technique for quantifying the effect of fibrinogen (Fbg) on blood coagulation, a dynamic study of d1/e of blood in various Fbg concentrations was performed in static state. Two groups of blood samples of hematocrit (HCT) in 35, 45, and 55% were reconstituted of red blood cells with: 1) treated plasma with its intrinsic Fbg removed and commercial Fbg added (0-8 g L(-1)); and 2) native plasma with commercial Fbg added (0-8 g L(-1)). The results revealed a typical behavior due to coagulation induced by calcium ions and the clotting time is Fbg concentration-dependent. The clotting time was decreased by the increasing amount of Fbg in both groups. Besides, the blood of lower HCT with various levels of Fbg took shorter time to coagulate than that of higher HCT. Consequently, the OCT method is a useful and promising tool for the detection of blood-coagulation processes induced with different Fbg levels.