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Titolo:
KINETICS OF THE BLACK-HOLE PHENOMENON IN ULTRASOUND BACKSCATTERING MEASUREMENTS WITH RED-BLOOD-CELL AGGREGATION
Autore:
QIN Z; DURAND LG; CLOUTIER G;
Indirizzi:
INST RECH CLIN MONTREAL,BIOMED ENGN LAB,110 AVE OINS OUEST MONTREAL PQ H2W 1R7 CANADA INST RECH CLIN MONTREAL,BIOMED ENGN LAB MONTREAL PQ H2W 1R7 CANADA UNIV MONTREAL,DEPT MED MONTREAL PQ H3C 3J7 CANADA
Titolo Testata:
Ultrasound in medicine & biology
fascicolo: 2, volume: 24, anno: 1998,
pagine: 245 - 256
SICI:
0301-5629(1998)24:2<245:KOTBPI>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
WHOLE-BLOOD; SHEAR RATE; ERYTHROCYTE AGGREGATION; MYOCARDIAL TISSUE; FLOW; ECHOGENICITY; ANISOTROPY; DEPENDENCE; SUSPENSIONS; BEHAVIOR;
Keywords:
ACOUSTIC BACKSCATTERING; BIOFLUID MECHANICS; ERYTHROCYTE AGGREGATION; POWER DOPPLER ULTRASOUND; BLACK HOLE PHENOMENON; ACOUSTIC ANISOTROPY; BIORHEOLOGY; MODEL;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
30
Recensione:
Indirizzi per estratti:
Citazione:
Z. Qin et al., "KINETICS OF THE BLACK-HOLE PHENOMENON IN ULTRASOUND BACKSCATTERING MEASUREMENTS WITH RED-BLOOD-CELL AGGREGATION", Ultrasound in medicine & biology, 24(2), 1998, pp. 245-256

Abstract

The observation of a hypoechoic zone around the center of large tubes(the ''black hole'' phenomenon) in ultrasound backscattering measurements with red blood cell (RBC) aggregation was reported for the first time in 1989. Since then, a very limited number of studies tried to explain its complex mechanisms. In this study, blood models characterized by different RBC aggregation levels were prepared by diluting horse blood plasma with a saline solution in different proportions. A laser reflectometry technique was used to characterize the RBC aggregation kinetics and cohesion forces between RBCs for each blood sample. The blood was circulated in a 12.7 mm diameter vertical tube. For each experimental flow condition tested, 25 or 15 power Doppler ultrasound measurements were performed across the tube with a 10-MHz system and insonation angles varying between 40 degrees to 70 degrees. For flow rates varying between 100 and 1250 mL/min, the ''black hole'' was observed inmost measurements performed with different aggregating RBC models. The ''black hole'' was more pronounced for RBCs with a high kinetics of aggregation and measurements with increasing Doppler angles. Previous studies suggested that this phenomenon is due to tube entrance effects, and the reduction of RBC aggregation at very low shear rates around the center of the tube. In the present study, the ''black hole'' was observed for shear rates up to 25 s(-1). It is suggested that the structural organization and orientation of RBC rouleaux may participate in the mechanism leading to the ''black hole'' phenomenon. A schematic representation of the rheological behavior of horse RBCs in a large tubeunder steady flow is presented. (C) 1998 World Federation for Ultrasound in Medicine & Biology.

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Documento generato il 29/11/20 alle ore 16:02:27