An investigation of an intra-operative PET imaging probe

We present a Monte Carlo simulation of an intraoperative PET imaging probe system with high spatial resolution capability. We have been investigating imaging systems in which a detector having high spatial resolution operates in conjunction with a conventional imaging system. Based on this concept, the intra-operative PET imaging probe system consists of a segment of a conventional PET scanner and a small PET imaging probe. The coincidence events between the segment of the conventional PET scanner and the small imaging probe are collected. The high spatial resolution is obtained due mainly to the imaging probe's proximity to the lesions and the small size crystals in the PET imaging probe. The PET imaging probe is equipped with a position tracker. By employing the position tracker, surgeons or clinicians can survey suspicious regions in detail by moving the probe during the imaging process. We cautiously expect that the image degradation due to limited-angle tomography will not be severe for small lesions in the near-field when using a simple listmode ordered-subsets EM algorithm for the image reconstruction. We plan to continue characterizing the proposed imaging system in terms of adaptive imaging described by Barrett and limited angle tomography.