Image improvement and design optimization of the time-of-flight PET.

Positron emission tomography (PET) with the added time-of-flight information has been shown to provide a better reconstructed image over conventional positron tomography. This improvement depends on the size of the object being imaged, the intrinsic resolution of the detector, and the time-of-flight resolution. Moreover, the signal-to-noise ratio of a PET image is related not only to the total number of counts in the image but also the event-locating uncertainties, the reconstruction filter function, and the recovered resolution in the image. This study provides a physical explanation for, and description of, the improvement in signal-to-noise ratio of a reconstructed image as a function of the crucial design parameters: time-of-flight timing resolution, intrinsic detector resolution, object size, and reconstructed image resolution.