Positron emission tomography–computed tomography (better known as<unk>  or<unk>  is a nuclear medicine technique which combines, in a single gantry, a positron emission tomography <unk>  scanner and an x-ray computed tomography <unk>  scanner, to acquire sequential images from both devices in the same session, which are combined into a single superposed (co-registered) image. Thus, functional imaging obtained by<unk> , which depicts the spatial distribution of metabolic or biochemical activity in the body can be more precisely aligned or correlated with anatomic imaging obtained by<unk>  scanning. Two- and three-dimensional image reconstruction may be rendered as a function of a common software and control system.<unk>  has revolutionized medical diagnosis in many fields, by adding precision of anatomic localization to functional imaging, which was previously lacking from pure<unk>  imaging. For example, many diagnostic imaging procedures in oncology, surgical planning, radiation therapy and cancer staging have been changing rapidly under the influence of<unk>  availability, and centers have been gradually abandoning conventional<unk>  devices and substituting them by<unk> s. Although the combined/hybrid device is considerably more expensive, it has the advantage of providing both functions as stand-alone examinations, being, in fact, two devices in one. The only other obstacle to the wider use of<unk>  is the difficulty and cost of producing and transporting the radiopharmaceuticals used for<unk>  imaging, which are usually extremely short-lived (for instance, the half life of radioactive fluorine-18 (18F) used to trace glucose metabolism (using fluorodeoxyglucose, FDG) is only two hours. Its production requires a very expensive cyclotron as well as a production line for the radiopharmaceuticals. At least one<unk>  radiopharmaceutical is made on site from a generator: Ga-68 from a gallium-68 generator.<unk> -MRI, like<unk> , combines modalities to produce co-registered images.
PET-CT
PET-MRI
Lymphadenectomy
FNA Mapping
Radiomics
Molecular imaging
Needle-localized biopsy
Open biopsy