Open AccessIdentification of chronic myocardial infarction with extracellular or intravascular contrast agents in magnetic resonance imaging
Author(s) -
WANG Jian,
LIU Hongyu,
LÜ Hang,
XIANG Bo,
GRUWEL Marco,
TOMANEK Boguslaw,
DESLAURIERS Roxanne,
TIAN Ganghong
Publication year - 2008
Publication title -
acta pharmacologica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.514
H-Index - 90
eISSN - 1745-7254
pISSN - 1671-4083
DOI - 10.1111/j.1745-7254.2008.00656.x
Subject(s) - medicine , magnetic resonance imaging , extracellular , myocardial infarction , gadolinium , gadodiamide , infarction , cardiology , nuclear medicine , radiology , chemistry , biochemistry , organic chemistry
Aim : To determine whether extracellular or intravascular contrast agents could detect chronic scarred myocardium in magnetic resonance imaging (MRI). Methods : Eighteen pigs underwent a 4 week ligation of 1 or 2 diagonal coronary arteries to induce chronic myocardial infarction. The hearts were then removed and perfused in a Langendorff apparatus. Eighteen hearts were divided into 2 groups. The hearts in groups I ( n =9) and II ( n =9) received the bolus injection of Gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA, 0.05 mmol/kg) and gadolinium‐based macromolecular agent (P792, 15 μmol/kg), respectively. First pass T 2 * MRI was acquired using a FLASH sequence. Delayed enhancement T 1 MRI was acquired with an inversion recovery prepared TurboFLASH sequence. Results : Wash‐in of both agents resulted in a sharp and dramatic T 2 * signal loss of scarred myocardium similar to that of normal myocardium. The magnitude and velocity of T 2 * signal recovery caused by wash‐out of extracellular agents in normal myocardium was significantly less than that in scarred myocardium. Conversely, the T 2 * signal of scarred and normal myocardium recovered to plateau rapidly and simultaneously due to wash‐out of intravascular agents. At the following equilibrium, extracellular agent‐enhanced T 1 signal intensity was significantly greater in scarred myocardium than in normal myocardium, whereas there was no significantly statistical difference in intravascular agent‐enhanced T 1 signal intensity between scarred and normal myocardium. Conclusion : After administration of extracellular agents, wash‐out T 2 * first‐pass and delayed enhanced T 1 MRI could identify scarred myocardium as a hyperenhanced region. Conversely, scarred myocardium was indistinguishable from normal myocardium during first‐pass and the steady state of intravascular agents.