title: Mapping myocardial viability using interleaved T1-T2* weighted imaging.
abstract: The present study was to evaluate the efficacy of our interleaved T1-T2* weighted imaging for assessing myocardial viability. The left anterior descending coronary artery (LAD) of pig hearts (n = 7) were occluded for 2 h, followed by 1 h reperfusion. After removed from animals, the hearts were perfused in a Langendorff apparatus with a mixture of pig blood and crystalloid solution in 1:1 ratio. T1 relaxation times of the myocardium were measured with a TurboFLASH inversion-recovery sequence. Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) (0.05 mmol/kg body wt) was then injected as a bolus into the aortic perfusion line. The first pass of the contrast agent through the heart was followed using the interleaved T1-T2* imaging sequence. Once the concentration of the contrast agent was in an equilibrium state, T1 relaxation times were measured again. It was found that the percentage recovery of T2* intensity (PRT2*) at the maximum T1 intensity measured during the first pass of the contrast agent with the interleaved T1-T2* imaging was significantly higher in infarcted myocardium than in normal myocardium. Moreover, the regions showing a high T2* percentage recovery on PRT2* maps matched well with the infarcted myocardium demarcated with triphenyl tetrazolium chloride (TTC) staining. We therefore conclude that infarcted myocardium can be delineated using the interleaved T1-T2* imaging method.
authors.affiliation: Institute for Biodiagnostics, National Research Council, Winnipeg, Man., Canada.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.forename: Guangping
authors.initials: G
authors.lastname: Dai
authors.forename: Bo
authors.initials: B
authors.lastname: Xiang
authors.forename: John
authors.initials: J
authors.lastname: Mark
authors.forename: Boguslaw
authors.initials: B
authors.lastname: Tomanek
authors.forename: Hongyu
authors.initials: H
authors.lastname: Liu
authors.forename: Roxanne
authors.initials: R
authors.lastname: Deslauriers
authors.forename: Ganghong
authors.initials: G
authors.lastname: Tian
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D003326:Coronary Circulation / Q000502:physiology; D004195:Disease Models, Animal; D019786:Gadolinium DTPA / Q000008:administration & dosage; D007275:Injections, Intravenous; D008279:Magnetic Resonance Imaging; D008863:Microspheres; D008955:Models, Cardiovascular; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology / Q000648:ultrastructure; D011859:Radiography; D013552:Swine
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA