An evaluation of dynamic SPECT imaging methods

Techniques to estimate dynamic parameters from data acquired in a single rotation of a single head SPECT camera are being investigated. We have tested the performance of various reconstruction methods. The linear least squares (LLS) method uses a simple assumption that the activity within each object pixel decreases over the imaging time. In simulations, we have used an analytical heart model with single and biexponential radiopharmaceutical decay, with and without background activity and noise. Studies using a single and a 90° dual head camera were modelled with a total acquisition time of 20 min, performing rotation over 180°. These simulations were followed by experimental scans of our dynamic phantom used with and without attenuation. Dynamic images from simulations and phantom experiments reconstruct well. The accuracy of reconstructed half-lives for the most challenging case of the single head camera remains within 10% for simulated data, and 20% for the phantom data. Some streaking artifacts which are evident in images corresponding to early reconstruction times subside upon incorporating constraints and regularizations