Assessment of myocardial function and perfusion in a canine model of non-occlusive coronary artery stenosis using fast magnetic resonance imaging.
Magnetic resonance (MR) functional and perfusion imaging were employed in a canine model of coronary artery stenosis (n = 6) for the quantification of functional and perfusion deficits before and after dipyridamole administration. Left anterior descending and circumflex (LCX) coronary blood flow were measured continuously after placing Doppler flowmeters. Inversion recovery gradient echo images during the transit of MR contrast medium gadolinium-benzyloxypropionictetraacetate dimeglumine (Gd-BOPTA/Dimeg) and fast breath-hold cine MR images were acquired at baseline, during LCX stenosis in basal state, and during LCX stenosis with vasodilation (dipyridamole 0.5 mg/kg). The extent of the functional defect and perfusion defect was expressed as percent of left ventricle (LV) circumference. During stenosis (LCX flow: 62.6 +/- 5.6% of baseline) the extent of the functional defect was slightly larger than the perfusion defect (11.0 +/- 1.8% versus 6.3 +/- 1.70% of LV circumference, respectively; P < 0.01). During vasodilation the extent of the functional defect was considerably smaller than the perfusion defect (25.3 +/- 2.5% versus 35.3 +/- 3.5%; P < 0.01). Thus, the sizes of ischemic regions displayed by MR perfusion defect and functional defect differ from each other.
Department of Radiology, University of California San Francisco, 94143-0628, USA.
J
J
Schwitter
M
M
Saeed
M F
MF
Wendland
H
H
Sakuma
J
J
Bremerich
E
E
Canet
C B
CB
Higgins
D000818:Animals; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology; D003327:Coronary Disease / Q000175:diagnosis*; D004176:Dipyridamole; D004285:Dogs; D005682:Gadolinium; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008536:Meglumine / Q000031:analogs & derivatives; D009200:Myocardial Contraction / Q000502:physiology; D017202:Myocardial Ischemia / Q000175:diagnosis*; D009206:Myocardium / Q000473:pathology*; D009942:Organometallic Compounds; D014665:Vasodilator Agents; D016277:Ventricular Function, Left / Q000502:physiology
D003287:Contrast Media; D009942:Organometallic Compounds; D014665:Vasodilator Agents; C064572:gadobenic acid; D004176:Dipyridamole; D008536:Meglumine; D005682:Gadolinium