Linked Life Data

11568171

Source:http://linkedlifedata.com/resource/pubmed/id/11568171

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2001-9-24
pubmed:abstractText
A noninvasive magnetic resonance imaging (MRI) method to assess the distribution of perfusion and metabolic demand (Q/VO(2)) in exercising human skeletal muscle is described. This method combines two MRI techniques that can provide accurate multiple localized measurements of Q/VO(2) during steady-state plantar flexion exercise. The first technique, (31)P chemical shift imaging, permits the acquisition of comparable phosphorus spectra from multiple voxels simultaneously. Because phosphocreatine (PCr) depletion is directly proportional to ATP hydrolysis, its relative depletion can be used as an index of muscle O(2) uptake (VO(2)). The second MRI technique allows the measurement of both spatially and temporally resolved muscle perfusion in vivo by using arterial spin labeling. Promising validity and reliability data are presented for both MRI techniques. Initial results from the combined method provide evidence of a large variation in Q/VO(2), revealing areas of apparent under- and overperfusion for a given metabolic turnover. Analysis of these data in a similar fashion to that employed in the assessment of ventilation-to-perfusion matching in the lungs revealed a similar second moment of the perfusion distribution and PCr distribution on a log scale (log SD(Q) and log SD(PCr)) (0.47). Modeling the effect of variations in log SD(Q) and log SD(PCr) in terms of attainable VO(2), assuming no diffusion limits, indicates that the log SD(Q) and log SD(PCr) would allow only 92% of the target VO(2) to be achieved. This communication documents this novel, noninvasive method for assessing Q/VO(2), and initial data suggest that the mismatch in Q/VO(2) may play a significant role in determining O(2) transport and utilization during exercise.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
91
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1845-53
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Local perfusion and metabolic demand during exercise: a noninvasive MRI method of assessment.
pubmed:affiliation
Department of Medicine, University of California-San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0623, USA. rrichardson@ucsd.edu
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't