Detection of infarct-related myocardial edema using cardiac diffusion-weighted magnetic resonance imaging.

A 50-year-old male was admitted to our hospital complaining of chest pain and was diagnosed with acute myocardial infarction of the lateral wall. Coronary angiography revealed an occlusion in the left circumflex coronary artery, which was successfully reperfused. Three days after reperfusion, cardiac magnetic resonance imaging was performed. Black-blood T2-weighted images (T2WIs) showed an area of slightly increased signal intensity (SI) in the lateral wall that was identified as infarct-related myocardial edema. Diffusion-weighted images (DWIs) acquired using a low b-value single-shot echo-planar sequence with combined cardiac and respiratory gating revealed an area of significantly increased SI in the same region identified as myocardial edema on T2WIs. The contrast-to-noise ratios of DWIs (76.9) was significantly higher than those of T2WIs (27.0). Our findings indicate that DWIs may provide better contrast in infarct-related myocardial edema than T2WIs.