Coronary artery stenosis: detection with contrast-enhanced MR imaging in dogs.
OBJECTIVE
To monitor with fast gradient-echo magnetic resonance (MR) imaging the dynamics of gadolinium benzyloxypropionictetraacetate (gadobenate) dimeglumine on myocardial signal intensity in dogs with critical left circumflex coronary artery stenosis.


METHODS
Fast gradient-echo MR images were acquired in a short axis of the left ventricle. Two bolus injections of 0.05 mmol/kg gadobenate dimeglumine were administered in the basal state after stenosis and after infusion of 0.5 mg/kg dipyridamole.


RESULTS
In the basal state, there was an equivalent increase in signal intensity of normal and hypoperfused myocardium during the first pass. Dipyridamole increased left anterior descending flow (287% +/- 36; P < .05) and decreased left circumflex flow (65% +/- 14; P < .05). The magnitude of signal intensity increase during the second bolus in the hypoperfused region was less than that of normal myocardium (P < .05). Contrast-enhanced images showed the hypoperfused region as smaller than the postmortem measurement (43.8% +/- 3.3; P < .05).


CONCLUSIONS
Contrast-enhanced fast MR imaging in the vasodilated state allows detection of hypoperfused myocardium in the presence of critical coronary stenosis.
Saeed
M
M
Department of Radiology, University of California, San Francisco 94143, USA.
Wendland
M F
MF
Sakuma
H
H
Geschwind
J F
JF
Derugin
N
N
Cavagna
F M
FM
Higgins
C B
CB
D000818:Animals; D003287:Contrast Media; D003326:Coronary Circulation / Q000187:drug effects; D003327:Coronary Disease / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D004176:Dipyridamole / Q000494:pharmacology; D004285:Dogs; D008279:Magnetic Resonance Imaging; D008536:Meglumine / Q000031:analogs & derivatives*; D009206:Myocardium / Q000473:pathology; D009942:Organometallic Compounds; D014664:Vasodilation / Q000187:drug effects
D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D004176:Dipyridamole; D008536:Meglumine