Multimodality imaging: An update on PET/CT technology

Introduction: Since their introduction in 2001, PET/CT systems have gained wide acceptance primarily due to their inherent ability to combine functional and structural information about the underlying disease state of the patient in a single imaging session. Their significance has also been documented with regard to their short imaging times, which minimize patient anxiety and image blurring due to patient motion. In the past seven years, PET/CT systems have replaced dedicated PET systems as the imaging modality of choice for diagnostic evaluation of oncology patients. Objectives: The purpose of this article is to review the evolution of PET/CT systems and document their current status. Discussion: Recent improvements in instrumentation are highlighted together with some outstanding issues that arise for specific PET/CT applications. These are followed by a description of some of the more common clinical applications of PET/CT imaging such as staging malignant disease, treatment planning, and monitoring therapy response. Finally, the future developments of PET/CT systems with regard to sensitivity, resolution, and new radiopharmaceuticals are discussed. The article concludes by presenting some issues concerning the next stage in the future of PET imaging, namely PET/MRI.