Linked Life Data

11370356

Source:http://linkedlifedata.com/resource/pubmed/id/11370356

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-5-23
pubmed:abstractText
Ultrasonic backscattering in blood including its dependence on the hematocrit, plasma proteins, shear rate, and flow disturbance, has been studied extensively theoretically and experimentally in vitro. However, much of the result has never been validated in vivo. To do so, backscattering measurements were made on pigs using a 10-MHz non-focused intravascular transducer in direct contact with blood. The probe was placed in either the abdominal aorta or the inferior vena cava. The backscattering coefficient (BSC) of blood flowing in these vessels as well as downstream from a stenosis was measured using an approach that was originally developed for measurements with focused transducers. With this approach, 6% porcine red cell saline suspensions prepared immediately after each in vivo measurement were used as the reference medium. Result from seven pigs at hematocrits ranging from 29 to 36% (31.9 +/- 2.5%) demonstrated that BSC of blood in the vena cava, (4.62 +/- 2.06) x 10(-5) cm-sr-1, is consistently higher than that in the aorta, (2.65 +/- 1.22) x 10(-5) cm-sr-1. The difference has been attributed to the lower shear rate and the formation of red cell aggregation in venous blood. These in vivo results are in agreement with those obtained in vitro. In response to stenoses created by ligating the aorta, backscattering of the blood measured downstream from the stenosis showed that the closer the site of measurement relative to the stenosis, the higher the backscatter, presumably resulting from the higher degree of flow disturbance. In vitro backscattering results on porcine whole blood were also acquired at 20 MHz with a Diasonics intravascular scanner.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0885-3010
pubmed:author
pubmed:issnType
Print
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
425-31
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
In vivo measurements of ultrasonic backscattering in blood.
pubmed:affiliation
Department of Biomedical Engineering, Chung Yuan Christian University, Chung Li, 32023, Taiwan. shyhhau@CYCU.edu.tw
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.