Manganese enhanced magnetic resonance imaging of normal and ischemic canine heart.

Hu TC, Christian TF, Aletras AH, Taylor JL, Koretsky AP, Arai AE.

Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892-1061, USA.

The ability of MnCl2 to enhance canine myocardium and to delineate ischemic areas is demonstrated. A dose-response curve was measured using T1 weighted images in 11 dogs. MnCl₂ (36, 113, 360, and 3600 micromol) was infused over a period of 3 min. Signal intensity increased linearly with MnCl₂ dose. At 113 micromol ( approximately 10 mi cromol/kg) the steady-state increase in intensity averaged 212 +/- 34%. No significant physiologic effects due to the infused MnCl₂ were detected except at the highest dose where there was a cardiac depressive effect. Ischemia was induced by occluding the left anterior descending coronary artery in 5 dogs. At an infused dose of 113 micromol, MnCl₂ clearly demarcated the ischemic zone during coronary occlusion. Contrast enhancement in the ischemic zone was less than 30% compared with normal tissue (P < 0.03). In conclusion, the intracellular contrast agent MnCl₂ enhances the canine heart and shows promise in detecting ischemia at doses that do not cause adverse cardiac effects.

PMID: 15968667 [PubMed - indexed for MEDLINE]