Dynamic SPECT imaging using a single camera rotation (dSPECT)

Techniques to estimate dynamic parameters from the data acquired during a s ingle rotation of a standard (single, dual and triple head) SPECT camera ar e being investigated. The performance of the constrained linear least squar es (C-LS) method is being assessed. This method uses a simple assumption th at 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 u sed an analytical heart model with single and bi-exponential activity decre ase, with and without background activity and statistical noise in the data . Studies using a single, a 90 degrees dual and a 120 degrees triple head c amera were modeled with a total acquisition time of 20min, performing rotat ion over 180 degrees. 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% en or ra nge. Some streaking artifacts which are evident in images corresponding to early reconstruction times subside upon incorporating further constraints a nd regularizations.