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Effect of cardiac flow on gradient recalled echo images of the canine heart
Author(s) -
Balaban Robert S.,
Taylor Joni F.,
Turner R.
Publication year - 1994
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.1940070114
Subject(s) - blood flow , intensity (physics) , occlusion , cardiology , coronary occlusion , oxygenation , coronary circulation , medicine , ischemia , fissipedia , venous blood , relaxation (psychology) , hemodynamics , chemistry , physics , quantum mechanics
The effect of coronary flow on the signal intensity of gradient recalled echo (GRE) MR images of the canine heart was evaluated at 4 T. Using a fully instrumented canine model, hyperperfusion (local adenosine infusion) and ischemia (local occlusion) were evaluated while coronary blood flow and venous oxygen tension were monitored. These studies demonstrated an increase in GRE signal intensity with increases in coronary blood flow and venous oxygenation. A local occlusion resulted in a small decrease in signal intensity in the affected area of the heart. The dependence of the signal changes on TE and TR indicated that the effects of high flow were associated with changes in the apparent T 2 and T 1 . Both relaxation effects could reflect changes in tissue blood volume associated with the conditions studied. In addition, the apparent T 2 changes were consistent with alterations in total tissue deoxyhemoglobin concentration and the changes in apparent T 1 were consistent with inflow effects.