Double-contrast MR imaging of reperfused porcine myocardial infarction. An experimental study using Gd-DTAA and Dy-DTPA-BMA.
OBJECTIVE
Myocardial infarctions were induced in 12 pigs to investigate whether a double-contrast method, combining a positive and a negative MR contrast agent, could improve the visualization of reperfused myocardial infarctions.


METHODS
All 12 pigs were subjected to 80 min of occlusion followed by reperfusion. In the double-contrast group (6 pigs), Gd-DTPA-BMA (0.3 mmol/kg b.w.) and Dy-DTPA-BMA (1.0 mmol/kg b.w.) were administered i.v. after 30 min of reperfusion. In the remaining 6 pigs, a single injection of Gd-DTPA-BMA (0.3 mmol/kg b.w.) was given after 30 min of reperfusion. All pigs were sacrificed 10 min post-contrast injection, corresponding to a reperfusion time of 40 min. The hearts were excised and imaged with MR. The concentrations of GD and Dy were measured in infarcted and nonischaemic myocardium using ICP-AES.


CONCLUSIONS
Contrast media concentrations were more than 4-fold higher in infarcted compared with nonischaemic myocardium. The infarctions were best shown on T1-weighted images, and there were no differences between the double and single contrast groups. In the T2-weighted images, the infarctions were significantly better visualized in the double-contrast group, due to a Dy-induced signal intensity loss in nonischaemic myocardium.
Nilsson
S
S
Department of Diagnostic Radiology, Akademiska Sjukhuset, University of Uppsala, Sweden.
Wikström
G
G
Ericsson
A
A
Wikström
M
M
Oksendal
A
A
Waldenström
A
A
Hemmingsson
A
A
D000818:Animals; D003287:Contrast Media; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D004419:Dysprosium; D005260:Female; D005682:Gadolinium; D019786:Gadolinium DTPA; D018810:Magnetic Resonance Angiography / Q000295:instrumentation / Q000379:methods*; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis*; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000473:pathology*; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives*; D013552:Swine
D003287:Contrast Media; D009942:Organometallic Compounds; C061756:sprodiamide; D004419:Dysprosium; D004369:Pentetic Acid; C064925:gadodiamide; D005682:Gadolinium; D019786:Gadolinium DTPA