Linked Life Data

7825374

Source:http://linkedlifedata.com/resource/pubmed/id/7825374

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1995-2-14
pubmed:abstractText
With the advent of ultrafast Magnetic Resonance Imaging (MRI), it is now possible to produce images with high temporal resolution. This gives the opportunity to record the passage of the paramagnetic contrast material Gadolinium-DTPA through the tissue of the heart muscle, yielding information on regional myocardial perfusion. We assessed the accuracy of MRI to detect and quantify reductions in coronary flow secondary to stenosis in dogs and patients. Regional blood flow was measured in dogs by left atrial injection of microspheres labeled with different radioactive isotopes. Signal intensity (SI) curves were generated in regions of interest over the myocardium and the cavum of the left ventricle. A newly developed two-compartment model based on the indicator-dilution method was used for interpretation of the SI-curves. In an optimization process the free parameters of the model equation were fitted to the measured SI-curves. The following flow parameters were determined: model parameter Q*, time to peak intensity (T), maximum signal intensity (SImax) and mean transit time (MTT) as calculated from a gamma variate fit. Absolute blood flow values were calculated for the parameters MTT and Q* assuming that the intravascular volume represents 10% of the total myocardial tissue volume. Measurements were performed on a 1.5 T Magnetom SP (Siemens AG, Erlangen) using a Turbo Flash sequence (TR = 6.5 ms, TE = 3 ms, TI = 100 ms, Flip Winkel = 9 degrees). Endsystolic images (voxel size = 1.8, 2.7, 15 mm3) were taken with an 18-cm Helmholtz surface coil in the short-axis view. A Gd-DTPA bolus (0.05 mmol/kg) was injected into the left atrium of 3 anesthetized closed-chest dogs. From the myocardial SI-curves the different parameters of myocardial perfusion were compared with flow assessed by microsphere injection over a wide range of myocardial blood flows (from 0.04 ml/min/g to 7.6 ml/min/g). A third-order polynominal fit showed a good correlation for the parameter Q* and MTT, whereas T and SImax were found to have a poor correlation. The linear regression analysis for a limited range of < 2 ml/min/g showed a superior estimation of myocardial perfusion for the parameter Q* than MTT. Blood flow > 2 ml/min/g was significantly underestimated by the MRT-measurements, but the parameter Q* showed the smallest amount of the divergent changes.(ABSTRACT TRUNCATED AT 400 WORDS)
pubmed:language
ger
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0300-5860
pubmed:author
pubmed:issnType
Print
pubmed:volume
83
pubmed:owner
NLM
pubmed:authorsComplete
N
pubmed:pagination
840-50
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:7825374-Adult, pubmed-meshheading:7825374-Aged, pubmed-meshheading:7825374-Animals, pubmed-meshheading:7825374-Blood Flow Velocity, pubmed-meshheading:7825374-Contrast Media, pubmed-meshheading:7825374-Coronary Circulation, pubmed-meshheading:7825374-Dipyridamole, pubmed-meshheading:7825374-Dogs, pubmed-meshheading:7825374-Female, pubmed-meshheading:7825374-Gadolinium DTPA, pubmed-meshheading:7825374-Humans, pubmed-meshheading:7825374-Magnetic Resonance Imaging, pubmed-meshheading:7825374-Male, pubmed-meshheading:7825374-Middle Aged, pubmed-meshheading:7825374-Myocardial Infarction, pubmed-meshheading:7825374-Myocardial Ischemia, pubmed-meshheading:7825374-Organometallic Compounds, pubmed-meshheading:7825374-Pentetic Acid, pubmed-meshheading:7825374-Reference Values, pubmed-meshheading:7825374-Regional Blood Flow
pubmed:year
1994
pubmed:articleTitle
[Quantitative evaluation of myocardial perfusion with ultrafast magnetic resonance tomography].
pubmed:affiliation
II. Med. Klinik, Universität Erlangen/Nürnberg.
pubmed:publicationType
Journal Article, English Abstract