Textural analysis of diffuse myocardial fibrosis in aging rats: A late gadolinium enhancement magnetic resonance imaging study

Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging has been shown to identify myocardial fibrosis secondary to myocardial infarction at nearly a cellular level. The purpose of this study is to assess diffuse myocardial fibrosis in aging hearts using LGE CMR imaging and histological staining as a reference. We present a quantitative approach to compare the amount of myocardial fibrosis between young (6-week-old) and elderly (2-year-old) rats. We hypothesize that 3D texture analysis of the high resolution MR images can characterize the level of diffuse fibrosis present in the myocardium and discriminate between the two age groups. Our results show the elderly hearts have an apparent increase of myocardial fibrosis in the histological slices stained with picrosirius red, which were qualitatively compared to the young group. The CMR quantification also shows a significant increase of myocardial fibrosis in the elderly group compared to the young rats. Furthermore, receiver operating characteristic curve analysis shows texture features derived from the MR images can distinguish between the two age groups better than signal intensity of the MR images. Our results suggest that texture analysis may improve the ability of detecting diffuse myocardial fibrosis in LGE CMR images.