Simulation study on system configuration refinement for the PET–laparoscope system—an intraoperative tool for surgical navigation in gastric cancer surgery

Positron emission tomography is used to diagnose gastric cancer and identify lymph node metastasis preoperatively. However, locating these lymph node metastases during surgery is difficult and usually leads to unnecessary node removal and results in a deterioration of a patient's quality of life. To improve the quality of life, intraoperative identification of lymph node metastasis is necessary. A positron emission tomography system consisting of an external detector array connected to the patient's surgical bed and a movable detector probe which is inserted into the patient's stomach along with a laparoscopic instrument has been proposed to identify lymph node metastasis intraoperatively. This study presents the image reconstruction of a system involving data acquisition using a movable detector. A simulation-based investigation on the refinement of the detector design is also presented. The image is reconstructed using a modified filtered back projection algorithm. In the simulation experiments, the proposed algorithms and detector setup successfully reconstructed images of radiation sources with better than 7-mm spatial resolution in a 2-min scan.