Magnetic resonance imaging of acute reperfused myocardial infarction: intraindividual comparison of ECIII-60 and Gd-DTPA in a swine model.
OBJECTIVE
To compare a necrosis-avid contrast agent (NACA) bis-Gd-DTPA-pamoic acid derivative (ECIII-60) after intracoronary delivery with an extracellular agent Gd-DTPA after intravenous injection on magnetic resonance imaging (MRI) in a swine model of acute reperfused myocardial infarction (MI).


METHODS
Eight pigs underwent 90 min of transcatheter coronary balloon occlusion and 60 min of reperfusion. After intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg, all pigs were scanned with T1-weighted MRI until the delayed enhancement of MI disappeared. Then they were intracoronarily infused with ECIII-60 at 0.0025 mmol/kg and imaged for 5 hr. Signal intensity, infarct-over-normal contrast ratio and relative infarct size were quantified, compared, and correlated with the results of postmortem MRI and triphenyltetrazolium chloride (TTC) histochemical staining.


RESULTS
A contrast ratio over 3.0 was induced by both Gd-DTPA and ECIII-60. However, while the delayed enhancement with Gd-DTPA virtually vanished in 1 hr, ECIII-60 at an 80x smaller dose depicted the MI accurately over 5 hr as proven by ex vivo MRI and TTC staining.


CONCLUSIONS
Both Gd-DTPA and ECIII-60 strongly enhanced acute MI. Comparing with fading contrast in a narrow time window with intravenous Gd-DTPA, intracoronary ECIII-60 persistently demarcated the acute MI, indicating a potential method for postprocedural assessment of myocardial viability after coronary interventions.
Jin
Jiyang
J
Department of Radiology, Zhongda Hospital of Southeast University, Nanjing, China.
Teng
Gaojun
G
Feng
Yi
Y
Wu
Yanping
Y
Jin
Qindi
Q
Wang
Yu
Y
Wang
Zhen
Z
Lu
Qin
Q
Jiang
Yibo
Y
Wang
Shengqi
S
Chen
Feng
F
Marchal
Guy
G
Ni
Yicheng
Y
D000818:Animals; D004396:Coloring Agents; D003287:Contrast Media / Q000378:metabolism / Q000494:pharmacology; D003331:Coronary Vessels; D004195:Disease Models, Animal; D019786:Gadolinium DTPA / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology; D007089:Image Enhancement / Q000379:methods; D007261:Infusions, Intra-Arterial; D007275:Injections, Intravenous; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009203:Myocardial Infarction / Q000209:etiology* / Q000473:pathology*; D015428:Myocardial Reperfusion Injury / Q000150:complications* / Q000473:pathology*; D009930:Organic Chemicals / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology; D012107:Research Design; D013194:Staining and Labeling / Q000379:methods; D013552:Swine; D013778:Tetrazolium Salts; D013997:Time Factors
D004396:Coloring Agents; D003287:Contrast Media; C471304:ECIII-60; D009930:Organic Chemicals; D013778:Tetrazolium Salts; C009591:triphenyltetrazolium; D019786:Gadolinium DTPA