Dynamic SPECT imaging using a single camera rotation (dSPECT)

Techniques to estimate dynamic parameters from the data acquired during a single rotation of a standard (single, dual and triple head) SPECT camera are being investigated. The performance of the constrained linear least squares (C-LS) method is being assessed. This method uses a simple assumption that the activity within each pixel at a given projection angle is less than or equal to the activity seen at the prior angle. In simulations, we have used an analytical heart model with single and bi-exponential activity decrease, with and without background activity and statistical noise in the data. Studies using a single, a 90° dual and a 120° triple head camera were modeled with a total acquisition time of 20 min, performing rotation over 1800. These simulations were followed by experimental scans of our dynamic phantom used with and without attenuation and subsequently a preliminary study involving a human subject was performed. Dynamic images from simulations and phantom experiments reconstruct well with an accuracy of reconstructed half-lives for most reconstructions within a 20% error range. Some streaking artifacts which are evident in images corresponding to early reconstruction times subside upon incorporating further constraints and regularizations