A new method of deriving the mice cardiovascular transit time without the need of region-of-interest drawing

In this study, we developed a simple and robust semiautomatic method to measure the right ventricle to left ventricle (RV-to-LV) transit time (TT) in mice using 2-[18F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). The accuracy of the new method was first evaluated using a 4-D digital dynamic mouse phantom. The RV-to-LV TTs of thirty-two mice studies were measured using the new method and compared to those obtained from the conventional ROI-drawing method. The results showed that the new method accurately separated different structures (e.g. RV, lung and LV) in the PET images and generated corresponding time activity curve (TAC) of each structure. The RV-to-LV TTs obtained from the new method and ROI method were not statistically different (p=0.31; r=0.77). We expect that this fast and robust method is applicable to study the pathophysiology of cardiovascular diseases using small animal models such as rats and mice.