Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1998-10-2
pubmed:abstractText
T2*-weighted gradient echo magnetic resonance images of rat brain were obtained dynamically during acute hypoxemic hypoxia to investigate the relations between changes in cerebral blood oxygen saturation (deltaYb), blood hematocrit (Hct), and R2* (deltaR2*). Images from hypoxemic rats with normal Hct (42.8%+/-2.33%; n=12) were compared with those from hypoxemic rats with mild (33.4%+/-1.88%; n=8) or moderate (27.14%+/-2.7%; n=10) reduction of Hct. A linear relation between deltaYb and deltaR2* was obtained for all three groups. However, the slopes of the linear regressions were statistically different from one another (P < 0.001), with the slopes of the regression lines increasing inversely with Hct; that is, the slope for normal Hct is less than the slope for mildly reduced Hct, which is less than the slope for moderately reduced Hct. These data suggest that for any given reduction in the oxygen saturation of cerebral blood, the deltaR2* will be of a lesser magnitude when the hemoglobin concentration is reduced; the data are consistent with existing theoretical models of deoxyhemoglobin content-dependent effects in T2*-weighted magnetic resonance imaging.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0271-678X
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1018-21
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Experimental hypoxemic hypoxia: effects of variation in hematocrit on magnetic resonance T2*-weighted brain images.
pubmed:affiliation
Mallinckrodt Institute of Radiology, Department of Electrical Engineering, Washington University, St. Louis, Missouri 63110, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.