Figure 4.

An example of a reperfused hemorrhagic myocardial infarction (arrow) shown by cardiac magnetic resonance imaging and the area at risk demonstrated with bifunctional staining method. A: The hyperenhanced transmural myocardial infarction (MI) was seen at the lateral wall on in vivo delay enhancement (DE) cardiac magnetic resonance imaging (cMRI); B: The ex vivo DE cMRI was highly correspondent with A; C: In contrast to the normal myocardium with red staining, the area at risk (AAR) was shown as an unstained region, on which the brown grayish area indicates a large intramural hemorrhagic infarction after the fixation by Formalin; D: On digital radiography (DR), the AAR was shown as non-opacified region in contrast to the opacified normal myocardium. Notice that the AAR defined by red iodized oil-staining (RIO-staining) in C and DR in D was somewhat larger than the MI defined by in vivo DE cMRI in A and ex vivo DE cMRI in B; E: The hematoxylin-eosin (HE) stained macroscopic view was obtained from the corresponding histological section of A, B, C, and D; F: Photomicroscopic view of the HE stained slice (magnification, × 100) confirmed the presence of myocardial necrosis with hemorrhage and tissue reaction. h: Hemorrhagic infarction; n: Adjacent normal myocardium with inflammatory infiltration.