Fig. 10

SPECT volume sensitivity, uniformity, and variability evaluated with a cylindrical phantom in MPH collimator measurement (left), SPH collimator measurement (middle), and SPH collimator simulation (right). The images present the central 0.25 mm-thick transverse slice from the MLEM reconstruction used in calculating volume uniformity and variability. Images were normalized by the maximum displayed pixel value, resulting in intensity values with arbitrary units (a.u.). A bubble can be seen in the measured data that was not modelled in the simulation. The SPH collimator offers a larger FOV with superior uniformity and noise characteristics compared to the MPH collimator when scanning relatively large distributions of radioactivity