Size determination of red blood cell aggregates induced by dextran using ultrasound backscattering phenomenon.

Applying Rayleigh theory of sound to blood medium, one can show that the scattered ultrasonic intensity is proportional to the 6th power of the size of the RBC aggregates. A statistical model of the blood structure is applied to evaluate the mean size of the aggregates. According to this model, the mean size of aggregates is independent of hematocrit for H≤40% and independent of the molecular weight of dextran for M≥150000 dalton