Using Spatial-Temporal Images for Analysis of Gated Cardiac Tomographic Data: The "M-Mode" Revisited

Recent advances in SPECT and PET technology permit ECG gating of tomographic cardiac images, allowing simultaneous measurement of 3D cardiac ventricular function with perfusion/metabolism. Extracting indices of regional function from these 4D data sets (3D space + time) remains a challenge. All approaches currently used to quantitate gated tomographic sequences deal separately with the spatial and temporal data. As functional information is based on close coupling between spatial and temporal changes, it could be beneficial to produce an image combining spatial and temporal information. In this paper we describe a method for producing such spatialtemporal images and, using gated FDG PET data, test the ability of these images to improve visual and quantitative assessment of cardiac function. Other potential schemes to make use of the space-time nature of this new representation are also discussed.