Fully 5d reconstruction of gated dynamic cardiac SPECT images using temporal B-splines

In previous work we explored a reconstruction approach based on B-spline modeling for dynamic cardiac images from a gated acquisition in single photon emission computed tomography (SPECT), of which the goal is to obtain a single sequence showing both cardiac motion and kinetic tracer distribution change over time simultaneously. In this work we further develop this approach by extending it to reconstruction of fully five-dimensional (5D) images. Besides quantifying its reconstruction accuracy, we also demonstrate the feasibility of using kinetic information from reconstructed dynamic images with this approach for differentiating defects from normal cardiac perfusion. The proposed approach is evaluated using a dynamic version of the 4D NURBS-based cardiac-torso (NCAT) phantom to simulate a gated SPECT perfusion acquisition with Tc99m Teboroxime. Our results demonstrate that, despite the greatly underdetermined nature of the problem, the 5D procedure can lead to faithful reconstruction of gated dynamic images for both cardiac motion and perfusion defect detection.