title: Analysis and interpretation of dynamic FDG PET oncological studies using data reduction techniques.
abstract: BACKGROUND
  Dynamic positron emission tomography studies produce a large amount of image data, from which clinically useful parametric information can be extracted using tracer kinetic methods. Data reduction methods can facilitate the initial interpretation and visual analysis of these large image sequences and at the same time can preserve important information and allow for basic feature characterization.
  
  
  METHODS
  We have applied principal component analysis to provide high-contrast parametric image sets of lower dimensions than the original data set separating structures based on their kinetic characteristics. Our method has the potential to constitute an alternative quantification method, independent of any kinetic model, and is particularly useful when the retrieval of the arterial input function is complicated. In independent component analysis images, structures that have different kinetic characteristics are assigned opposite values, and are readily discriminated. Furthermore, novel similarity mapping techniques are proposed, which can summarize in a single image the temporal properties of the entire image sequence according to a reference region.
  
  
  RESULTS
  Using our new cubed sum coefficient similarity measure, we have shown that structures with similar time activity curves can be identified, thus facilitating the detection of lesions that are not easily discriminated using the conventional method employing standardized uptake values.
authors.affiliation: Biomedical Engineering Laboratory, School of Electrical and Computer Engineering, National Technical University of Athens, GR-15773 Athens, Greece. spav@biomed.ntua.gr
authors.forename: Sotiris
authors.initials: S
authors.lastname: Pavlopoulos
authors.forename: Trias
authors.initials: T
authors.lastname: Thireou
authors.forename: George
authors.initials: G
authors.lastname: Kontaxakis
authors.forename: Andres
authors.initials: A
authors.lastname: Santos
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D003627:Data Interpretation, Statistical; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D009369:Neoplasms / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods*; D025341:Principal Component Analysis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18