Estimating the distribution of myocardial fibrosis after myocardial infarct is important for appropriate therapeutic
planning. Here, we applied a Raman confocal microscope equipped with slit scanner for molecular tissue imaging of rat
infarcted hearts. Raman spectra of the cytoplasm of cardiomyocytes included the resonance Raman bands at 751, 1130
and 1582 cm-1 arising mainly from reduced b- and c- type cytochromes. Raman spectra of fibrotic tissues at the borderzone
of old myocardial infarct were highly consistent with that of collagen type I. Based on these findings, we
successfully obtained Raman tissue images of a cardiomyocyte and surrounding collagen at the cellular level.