title: A Study on the Basic Criteria for Selecting Heterogeneity Parameters of F18-FDG PET Images.
abstract: Textural analysis might give new insights into the quantitative characterization of metabolically active tumors. More than thirty textural parameters have been investigated in former F18-FDG studies already. The purpose of the paper is to declare basic requirements as a selection strategy to identify the most appropriate heterogeneity parameters to measure textural features. Our predefined requirements were: a reliable heterogeneity parameter has to be volume independent, reproducible, and suitable for expressing quantitatively the degree of heterogeneity. Based on this criteria, we compared various suggested measures of homogeneity. A homogeneous cylindrical phantom was measured on three different PET/CT scanners using the commonly used protocol. In addition, a custom-made inhomogeneous tumor insert placed into the NEMA image quality phantom was imaged with a set of acquisition times and several different reconstruction protocols. PET data of 65 patients with proven lung lesions were retrospectively analyzed as well. Four heterogeneity parameters out of 27 were found as the most attractive ones to characterize the textural properties of metabolically active tumors in FDG PET images. These four parameters included Entropy, Contrast, Correlation, and Coefficient of Variation. These parameters were independent of delineated tumor volume (bigger than 25-30 ml), provided reproducible values (relative standard deviation< 10%), and showed high sensitivity to changes in heterogeneity. Phantom measurements are a viable way to test the reliability of heterogeneity parameters that would be of interest to nuclear imaging clinicians.
authors.affiliation: Scanomed Nuclear Medicine Center, Debrecen, Debrecen, Hungary.|Department of Nuclear Medicine, Faculty of Medicine, University of Debrecen, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Forgacs
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, University of Debrecen, Hungary.
authors.forename: Hermann
authors.initials: H
authors.lastname: Pall Jonsson
authors.affiliation: Ahmanson Biological Imaging Center, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at University of California at Los Angeles, California, United States of America.
authors.forename: Magnus
authors.initials: M
authors.lastname: Dahlbom
authors.affiliation: Alfred Mann Institute for Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America.
authors.forename: Freddie
authors.initials: F
authors.lastname: Daver
authors.affiliation: Quantitative Imaging and Medical Physics at Medical University of Vienna, Vienna, Austria.
authors.forename: Matthew
authors.initials: M
authors.lastname: D DiFranco
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, University of Debrecen, Hungary.
authors.forename: Gabor
authors.initials: G
authors.lastname: Opposits
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, University of Debrecen, Hungary.
authors.forename: Aron
authors.initials: A
authors.lastname: K Krizsan
authors.affiliation: Scanomed Nuclear Medicine Center, Debrecen, Debrecen, Hungary.|Department of Nuclear Medicine, Faculty of Medicine, University of Debrecen, Hungary.
authors.forename: Ildiko
authors.initials: I
authors.lastname: Garai
authors.affiliation: Ahmanson Biological Imaging Center, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at University of California at Los Angeles, California, United States of America.
authors.forename: Johannes
authors.initials: J
authors.lastname: Czernin
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, University of Debrecen, Hungary.
authors.forename: Jozsef
authors.initials: J
authors.lastname: Varga
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, University of Debrecen, Hungary.
authors.forename: Lajos
authors.initials: L
authors.lastname: Tron
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, University of Debrecen, Hungary.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Balkay
mesh_terms: D019788:Fluorodeoxyglucose F18 / Q000032:analysis*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D019047:Phantoms, Imaging; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000032:analysis*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18