Visualization of myocardial microstructure using high-resolution T*2 imaging at high magnetic field

The analysis of myocardial microstructure in vivo is important for the determination of myocardial contractility and function. The purpose of the present study was to demonstrate that high-resolution T*2 imaging has the potential to visualize the microstructure of beating, isolated rat hearts. To perform T*2 imaging, a multiple gradient-echo sequence was implemented on an 11.75 Tesla microscopy system. An in-plane resolution of 78 microm and a slice thickness of 250 microm were achieved in 24 min. In comparison to histological sections, the T*2 maps showed an excellent spatial correspondence to the myocardial fiber structure. To demonstrate the utility of this technique, morphologic alterations in myocardial microstructure were investigated in hearts with chronic myocardial infarction. Scar tissue and the extent of the infarcted region were clearly visualized and quantified using high-resolution T*2 imaging.