Journal of Ultrasound in Medicine, Vol 8, Issue 8 425-434, Copyright © 1989 by American Institute of Ultrasound in Medicine
Echoicity of whole blood
Y. W. Yuan and K. K. Shung
Bioengineering Program, Penn State University, University Park 16802.
A clear relationship was found to exist when the echoicity of whole blood
under different flow conditions was determined and related to its
corresponding ultrasonic backscattering properties. The results indicate
that the echoicity of whole blood is shear rate and species dependent.
Echoicity of porcine whole blood was found to decrease as the shear rate
was increased, whereas the echoicity of bovine whole blood was found to be
shear rate independent. At the same shear rate and hematocrit, the
echoicity of human and porcine whole blood was found to be higher than that
of bovine whole blood. These observations can be readily understood when
red cell aggregation is considered. In imaging porcine whole blood under
steady laminar flow, under certain conditions a hypoechoic region was
observed to appear near the center of the flow conduit. The behavior of
this hypoechoic region and the mechanisms responsible for its appearance
are not entirely clear at present.
