A hybrid rotation-translation (HRT) scan scheme for in vivo animal SPECT imaging on a stationary scanner

We developed SPECT imaging capability on an animal PET scanner by placing a slit-slat collimator inside the PET detector gantry. To perform in vivo animal imaging with minimal gravity induced animal motion, we investigated the performance of hybrid rotation-translation (HRT) tomographic scan scheme in this paper. Three evaluation indices, i.e. sampling completeness (SC), sensitivity, and directional spatial resolution (DR), were designed and calculated throughout the field-of-view to assess the performance of the HRT and the conventional rotation-only scan scheme. The reconstructed image quality was evaluated through simulated and experimental studies. Ten HRT schemes with different rotation and translation combinations and the conventional rotation-only scheme were tested. General HRT schemes (containing both rotational and translational movements) have comparable sampling completeness (SC), comparable sensitivity and better spatial resolution (in terms of both DR and visual image quality), as compared to the conventional rotation-only scheme We concluded that HRT scan scheme enables in vivo animal SPECT imaging on the stationary scanner and has the advantage of improving image resolution.