M. Jerosch-herold et al., Direct comparison of an intravascular and an extracellular contrast agent for quantification of myocardial perfusion, INT J CAR I, 15(6), 1999, pp. 453-464
A direct comparison of extracellular and intravascular contrast agents for
the assessment of myocardial perfusion was carried out in a porcine model (
N = 5) with a flow-limiting occluder on the left anterior descending corona
ry artery. Rapid imaging during the first pass of an extracellular or intra
vascular contrast agent with a saturation-recovery-prepared TurboFLASH sequ
ence showed comparable peak contrast-to-noise enhancements in myocardial ti
ssue regions with flows averaging 1.1 +/- 0.2 at baseline to 4.8 +/- 0.6 ml
/min/g during hyperemia. The coefficient of variation between the MR estima
tes of blood flow with Gadomer-17 and the microsphere blood flow measuremen
ts was 11 +/- 11, while the corresponding coefficient of variation for bloo
d flow estimates with the extracellular CA was 23 +/- 11. Blood volume diff
erences between rest and hyperemia observed with the intravascular tracer w
ere significant (V-vasc(rest) = 0.078 +/- 0.013 ml/g, versus V-vasc(hyperem
ia) = 0.102 +/- 0.019 ml/g; p < 0.05). The effects of water exchange were m
inimized through the choice of pulse sequence parameters to provide blood v
olume estimates consistent with the changes expected between rest and hyper
emia. This study represents the first application of multiple indicators in
first pass imaging studies for the assessment of myocardial perfusion. The
use of an intravascular instead of an extracellular contrast agent allows
a reduction of the degrees of freedom for modeling tissue residue curves an
d results in improved accuracy of blood flow estimates.