Sh. Zhao et al., Magnetic susceptibility of Dy-DTPA-BMA to reperfused myocardial infarctionin an excised dog heart model: evidence of viable myocardium, CHIN MED J, 113(3), 2000, pp. 260-264
Objective To assess the effects of Dy-DTPA-BMA (sprodiamide) on ex-vivo MR
imaging of reperfused acute myocardial infarction.
Methods Eighteen dogs were subjected to 2-hour coronary artery occlusion fo
llowed by 24-hour reperfusion. Dysprosium-chelate (Dy-DTPA-BMA) was injecte
d into 16 dogs. Twenty minutes before their sacrifice. Two dogs did not rec
eive the contrast medium and were used as controls. Excised hearts were ima
ged on T2-weighted spin-echo sequence (T2W SE) and T2*-weighted gradient re
called echo sequence (T2*W GRE), then sectioned and double-perfused for pla
nimetric comparison.
Results Dy-DTPA-BMA induced myocardial signal loss was detected on T2W SE a
nd on T2*W GRE images. The signal loss was observed at the subendocardial l
ocation of the myocardial wall inducing an apparent enlargement of the left
ventricle cavity and a thinning appearance of the anterior myocardial wall
.
Conclusions Myocyte necrosis diminishes the potency of dysprosium to cause
MR imaging signal intensity loss in reperfused myocardial infarction. Pre-i
nfarcted myocardium with potentially reversible viability may be responsibl
e for the effect of the contrast medium.