title: Evaluation of compartmental and spectral analysis models of [18F]FDG kinetics for heart and brain studies with PET.
abstract: Various models have been proposed to quantitate from [18F]-Fluoro-Deoxy-Glucose ([18F]FDG) positron emission tomography (PET) data glucose regional metabolic rate. We evaluate here four models, a three-rate constants (3K) model, a four-rate constants (4K) model, an heterogeneous model (TH) and a spectral analysis (SA) model. The data base consists of [18F]FDG dynamic data obtained in the myocardium and brain gray and white matter. All models were identified by nonlinear weighted least squares with weights chosen optimally. We show that: 1) 3K and 4K models are indistinguishable in terms of parsimony criteria and choice should be made on parameter precision and physiological plausibility; in the gray matter a more complex model than the 3K one is resolvable; 2) the TH model is resolvable in the gray but not in the white matter; 3) the classic SA approach has some unnecessary hypotheses built in and can be in principle misleading; we propose here a new SA model which is more theoretically sound; 4) this new SA approach supports the use of a 3K model in the heart with a 60 min experimental period; it also indicates that heterogeneity in the brain is modest in the white matter; 5) [18F]FDG fractional uptake estimates of the four models are very close in the heart, but not in the brain; 6) a higher than 60 min experimental time is preferable for brain studies.
authors.affiliation: Department of Electronics and Informatics, University of Padova, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bertoldo
authors.forename: P
authors.initials: P
authors.lastname: Vicini
authors.forename: G
authors.initials: G
authors.lastname: Sambuceti
authors.forename: A A
authors.initials: AA
authors.lastname: Lammertsma
authors.forename: O
authors.initials: O
authors.lastname: Parodi
authors.forename: C
authors.initials: C
authors.lastname: Cobelli
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D005462:Fluorine Radioisotopes; D005947:Glucose / Q000378:metabolism*; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D014055:Tomography, Emission-Computed
chemical_list: D005462:Fluorine Radioisotopes; D003847:Deoxyglucose; D005947:Glucose