title: A combined PET/CT scanner: the path to true image fusion.
abstract: Software-based image fusion is used routinely for the alignment of functional and anatomical images of the brain. For other parts of the body, image registration is more problematic owing to differences in patient positioning, scanner bed profiles and the involuntary movement of internal organs. An alternative to the software approach is a scanner that acquires both function and anatomy during a single imaging session: a fusion of the technologies rather than a fusion of the images post hoc. Consequently, we designed and built a prototype combined PET and CT scanner comprising a clinical CT and a clinical PET scanner mounted together in a single gantry. Over 300 cancer patients have been imaged in the scanner to establish the clinical value of the combined PET/CT approach. The CT images were used to provide essentially noiseless attenuation correction factors for the PET data. The widespread interest created by the patient studies acquired with the prototype PET/CT stimulated commercial activity and several major vendors of medical imaging equipment now offer combined PET/CT designs. This paper reviews the development of the combined PET/CT scanner, and illustrates the clinical aspects with some typical studies in cancer patients. The potential impact on medical practice of the commercial availability of PET/CT scanner technology at affordable cost is assessed.
authors.affiliation: Department of Radiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA. townsenddw@msx.upmc.edu
authors.forename: David W
authors.initials: DW
authors.lastname: Townsend
authors.forename: Thomas
authors.initials: T
authors.lastname: Beyer
mesh_terms: D000368:Aged; D023881:Colonography, Computed Tomographic; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging; D004867:Equipment Design; D005260:Female; D019788:Fluorodeoxyglucose F18; D005544:Forecasting; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D015898:Tomography Scanners, X-Ray Computed; D014055:Tomography, Emission-Computed / Q000295:instrumentation* / Q000639:trends; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18