Manganese-Enhanced T₁ Mapping in the Myocardium of Normal and Infarcted Hearts

Figure 2

T₁ shortening of manganese contrast media over time. (a) Normalized T₁ maps acquired subsequent to infusion of MnCl₂, EVP1001-1, and mangafodipir at 20 minute intervals up to 60 minutes, with associated gradient echo cine images in end-diastole and end-systole. MnCl₂ (22 μmol/kg), EVP1001-1 (22 μmol/kg) or mangafodipir (44 μmol/kg) was administered intravenously to isoflurane-anaesthetised healthy rats over 3-4 minutes. Rats were simultaneously administered an infusion of 8 mL/kg 0.9% saline over 3-4 minutes. Note the superior degree of T₁ shortening with MnCl₂, and EVP1001-1 at half the molar dosage of manganese as compared with mangafodipir (T₁ reduction of 421.3 ms and 357.9 ms from baseline with MnCl₂ and EVP1001-1 compared with 222.7 ms with mangafodipir). (b) Reduction in mean left ventricular T₁ values over 60 minutes with EVP1001-1 and mangafodipir. MnCl₂ (22 μmol/kg; blue), EVP1001-1 (22 μmol/kg; red), mangafodipir (22 (green) or 44 (purple) μmol/kg) was administered to rats ( per group) over 3-4 min. Error bars represent standard deviations from time points where measurements were recorded ( at each time point). Two-way ANOVA confirmed a dependence of mean myocardial T₁ shortening between each of the contrast agents ().

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