An integrated PET-CT simulation pipeline for biomedical imaging research
Positron emission tomography-computed tomography (PET-CT) is a frequently used multimodality imaging technique. PET scans utilize a radioactive tracer to record metabolic activity, and CT scans provide anatomical information through x-ray attenuation. The combined use of these imaging techniques allows for enhanced lesion detection, improved tumor localization, and radiomics analyses. The essential utility of dual-modality imaging may only be fully ascertained through imaging trials. Such imaging experiments can be uniquely performed using virtual imaging trials with advantageous such as practicality, low costs, and access to ground truth. The purpose of this study was to develop a fully integrated and validated PET-CT simulation pipeline, enabling virtual imaging trials for dual modality applications. The developed simulator models both CT and PET acquisition processes, aligns the spatial domains to ensure a registered geometry between the modalities, and reconstructs the PET acquisition data. The PET-CT simulator was verified by imaging a four-dimensional extended cardiac-torso (XCAT) phantom with 18F-FDG uptake and producing fusion PET-CT images following reconstruction. The simulator was further validated against experimental measurements using a NEMA IEC phantom scanned on a real Discovery MI 5 ring PET-CT scanner. The verification and validation results demonstrated anticipated radionuclide uptake regions, properly registered emission and attenuation data for dual-modality imaging analysis, and acceptable agreement between simulated and experimental measurements. Overall, the developed pipeline demonstrated to be a viable tool for PET-CT virtual imaging trials.
