Cy. Tong et al., MEASUREMENT OF THE EXTRACTION EFFICIENCY AND DISTRIBUTION VOLUME FOR GD-DTPA IN NORMAL AND DISEASED CANINE MYOCARDIUM, Magnetic resonance in medicine, 30(3), 1993, pp. 337-346
We have previously shown that the myocardial Gd-DTPA concentration ([
Gd-DTPA]t(t)) after a bolus injection of Gd-DTPA can be predicted by t
he Modified Kety Equation (MKE). If [Gd-DTPA]t(t) can be determined by
MRI and the data fit to the MKE, then the distribution volume (lambda
) of Gd-DTPA and the myocardial flow (F) times the extraction efficien
cy (E), i.e., the FE product, can be determined. Therefore F can only
be quantified if E is known. We measured the global E in vivo in norma
l canine myocardium, and measured E and lambda, in vitro, locally in n
ormal, acute ischemic (n = 5; coronary artery occlusion < 4 h), infarc
ted (n = 4; coronary artery occlusion, 6 days) and reperfused (n = 4;
coronary artery occlusion 2 h, and reperfusion 2 h and 6 days) myocard
ium. Results indicate that E differs with F and with individuals and c
onsequently, F cannot be quantified using the MKE unless the local E i
s also determined in vivo.