Roles of myocardial blood volume and flow in coronary artery disease: an experimental MRI study at rest and during hyperemia.
OBJECTIVE
To validate fast perfusion mapping techniques in a setting of coronary artery stenosis, and to further assess the relationship of absolute myocardial blood volume (MBV) and blood flow (MBF) to global myocardial oxygen demand.


METHODS
A group of 27 mongrel dogs were divided into 10 controls and 17 with acute coronary stenosis. On 1.5-T MRI, first-pass perfusion imaging with a bolus injection of a blood-pool contrast agent was performed to determine myocardial perfusion both at rest and during either dipyridamole-induced vasodilation or dobutamine-induced stress. Regional values of MBF and MBV were quantified by using a fast mapping technique. Color microspheres and (99m)Tc-labeled red blood cells were injected to obtain respective gold standards.


RESULTS
Microsphere-measured MBF and (99m)Tc-measured MBV reference values correlated well with the MR results. Given the same changes in MBF, changes in MBV are twofold greater with dobutamine than with dipyridamole. Under dobutamine stress, MBV shows better association with total myocardial oxygen demand than MBF. Coronary stenosis progressively reduced this association in the presence of increased stenosis severity.


CONCLUSIONS
MR first-pass perfusion can rapidly estimate regional MBF and MBV. Absolute quantification of MBV may add additional information on stenosis severity and myocardial viability compared with standard qualitative clinical evaluations of myocardial perfusion.
McCommis
Kyle S
KS
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA. mccommisk@mir.wustl.edu
Goldstein
Thomas A
TA
Abendschein
Dana R
DR
Misselwitz
Bernd
B
Pilgram
Thomas
T
Gropler
Robert J
RJ
Zheng
Jie
J
D000818:Animals; D001783:Blood Flow Velocity; D001810:Blood Volume; D003324:Coronary Artery Disease / Q000150:complications* / Q000503:physiopathology*; D003326:Coronary Circulation; D004285:Dogs; D006940:Hyperemia / Q000150:complications* / Q000503:physiopathology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D055420:Perfusion Imaging / Q000379:methods*