MRI quantitative myocardial perfusion with compartmental analysis: a rest and stress study.
K1 (first-order transfer constant from arterial plasma to myocardium for Gd-DTPA) and Vd (distribution volume of Gd-DTPA in myocardium) were measured in vivo in a canine model (n = 5) using MRI-derived myocardial perfusion curves and a compartmental model. Perfusion curves were obtained after a bolus injection of Gd-DTPA (0.04 mM/kg) with an inversion-prepared fast gradient echo sequence. Myocardium and blood signal intensity were converted to a concentration of Gd-DTPA, according to a model appropriate for short (<1 s) interimage intervals characteristic of cardiac-triggered acquisitions. Before dipyridamole-induced stress, K1 and Vd, obtained from the fit of the MRI-derived perfusion curves, were 6.2 +/- 1.4 (mHz) and 17.5 +/- 4.2%, respectively. After dipyridamole infusion, a K1 increase of a factor of 2.82 +/- 0.72 was measured (P = 0.003). No change was observed in Vd (P = 0.98). These results suggest that the K1 increase after dipyridamole reflects a flow-related effect that can be useful to quantify the MRI-derived perfusion curves.
Vallée
J P
JP
Center of Advanced Magnetic Resonance Development, Duke University Medical Center, Durham, North Carolina, USA.
Sostman
H D
HD
MacFall
J R
JR
Wheeler
T
T
Hedlund
L W
LW
Spritzer
C E
CE
Coleman
R E
RE
D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D003326:Coronary Circulation / Q000502:physiology*; D004176:Dipyridamole / Q000494:pharmacology; D004285:Dogs; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006321:Heart / Q000187:drug effects; D008279:Magnetic Resonance Imaging; D008962:Models, Theoretical; D010477:Perfusion; D012146:Rest; D013312:Stress, Physiological; D014665:Vasodilator Agents / Q000494:pharmacology
D003287:Contrast Media; D014665:Vasodilator Agents; D004176:Dipyridamole; D019786:Gadolinium DTPA