title: Conversion of arterial input functions for dual pharmacokinetic modeling using Gd-DTPA/MRI and 18F-FDG/PET.
abstract: Reaching the full potential of magnetic resonance imaging (MRI)-positron emission tomography (PET) dual modality systems requires new methodologies in quantitative image analyses. In this study, methods are proposed to convert an arterial input function (AIF) derived from gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) in MRI, into a (18)F-fluorodeoxyglucose ((18)F-FDG) AIF in PET, and vice versa. The AIFs from both modalities were obtained from manual blood sampling in a F98-Fisher glioblastoma rat model. They were well fitted by a convolution of a rectangular function with a biexponential clearance function. The parameters of the biexponential AIF model were found statistically different between MRI and PET. Pharmacokinetic MRI parameters such as the volume transfer constant (K(trans)), the extravascular-extracellular volume fraction (ν(e)), and the blood volume fraction (ν(p)) calculated with the Gd-DTPA AIF and the Gd-DTPA AIF converted from (18)F-FDG AIF normalized with or without blood sample were not statistically different. Similarly, the tumor metabolic rates of glucose (TMRGlc) calculated with (18) F-FDG AIF and with (18) F-FDG AIF obtained from Gd-DTPA AIF were also found not statistically different. In conclusion, only one accurate AIF would be needed for dual MRI-PET pharmacokinetic modeling in small animal models.
authors.affiliation: Centre d'Imagerie Moléculaire de Sherbrooke, Département de Médecine Nucléaire et Radiobiologie, Université de Sherbrooke, 3001 12e Avenue Nord, Sherbrooke, Quebec, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Poulin
authors.forename: Réjean
authors.initials: R
authors.lastname: Lebel
authors.forename: Etienne
authors.initials: E
authors.lastname: Croteau
authors.forename: Marie
authors.initials: M
authors.lastname: Blanchette
authors.forename: Luc
authors.initials: L
authors.lastname: Tremblay
authors.forename: Roger
authors.initials: R
authors.lastname: Lecomte
authors.forename: M'hamed
authors.initials: M
authors.lastname: Bentourkia
authors.forename: Martin
authors.initials: M
authors.lastname: Lepage
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000098:blood supply / Q000175:diagnosis / Q000378:metabolism*; D045744:Cell Line, Tumor; D003198:Computer Simulation; D003287:Contrast Media / Q000493:pharmacokinetics; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D005909:Glioblastoma / Q000175:diagnosis / Q000378:metabolism*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008954:Models, Biological; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D011916:Rats, Inbred F344; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D019786:Gadolinium DTPA