title: A dual radiologic contrast agent protocol for 18F-FDG and 18F-FLT PET/CT imaging of mice bearing abdominal tumors.
abstract: OBJECTIVE
  The aim of the study was to improve abdominal tumor detection by use of a dual radiologic contrast protocol.
  
  
  METHODS
  eXia160® (Benitio international) was mixed with 2-deoxy-2-[¹⁸F]fluoro-D: -glucose or 3'-[¹⁸F]fluoro-3'-deoxythymidine for intravenous (IV) injections. Omnipaque® 300 (GE healthcare) was used for intraperitoneal (IP) injections. Positron emission tomography/computed tomography (PET/CT) scans were acquired on a Siemens Biograph® equipped with point spread function reconstruction. The optimal concentration and injection schedule of IP contrast agent was studied in 12 mice. The impact of IP contrast media on PET quantitative accuracy was investigated by phantom studies and by imaging six mice before and after IP injection of Omnipaque®. The impact of a dual contrast media protocol on tumor delineation and quantitation was evaluated in 15 tumor-bearing mice using ex vivo counting as the reference.
  
  
  RESULTS
  The optimal sequence was a mixture of tracer plus IV contrast agent followed by 1 mL of IP contrast agent (20 mg iodine/mL) administered 10 min before PET/CT acquisition. Phantom studies showed that the use of a 20-mg iodine/mL concentration of Omnipaque® led to a 4.8% overestimation of radioactivity concentration, as compared to saline. This was confirmed by animal studies that demonstrated a 4.3% overestimation. Tumor detection was excellent and correlation between PET/CT quantitative data and ex vivo counting was good (r² = 0.91, slope = 0.7).
  
  
  CONCLUSIONS
  A dual radiologic contrast protocol is useful in PET/CT scanning of mice bearing abdominal tumors. Contrast agents used in this manner lead to a small but acceptable overestimation of quantitative PET data.
authors.affiliation: Bioticla Team, EA 1772, IFR 146 ICORE, GRECAN, François Baclesse Cancer Centre and Caen University, Caen, France. n.aide@baclesse.fr.|PET Centre, Caen University Hospital and François Baclesse Cancer Centre, Caen, France. n.aide@baclesse.fr.|Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia. n.aide@baclesse.fr.|Nuclear Medicine Department, Centre François Baclesse, Avenue Général Harris, 14076, Caen cedex 5, France. n.aide@baclesse.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Aide
authors.affiliation: Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.|Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Australia.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Kinross
authors.affiliation: Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.
authors.forename: Jean-Mathieu
authors.initials: JM
authors.lastname: Beauregard
authors.affiliation: Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.
authors.forename: Oliver
authors.initials: O
authors.lastname: Neels
authors.affiliation: Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Australia.
authors.forename: Titaina
authors.initials: T
authors.lastname: Potdevin
authors.affiliation: Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Roselt
authors.affiliation: Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.|Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Australia.
authors.forename: Donna
authors.initials: D
authors.lastname: Dorow
authors.affiliation: Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Australia.
authors.forename: Carleen
authors.initials: C
authors.lastname: Cullinane
authors.affiliation: Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.|Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Australia.|The Department of Medicine, The University of Melbourne, Parkville, Australia.
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Hicks
mesh_terms: D000008:Abdominal Neoplasms / Q000000981:diagnostic imaging*; D000818:Animals; D001201:Ascites / Q000473:pathology; D003287:Contrast Media / Q000008:administration & dosage; D015224:Dideoxynucleosides / Q000008:administration & dosage; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage; D007275:Injections, Intravenous; D051379:Mice; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D015224:Dideoxynucleosides; D019788:Fluorodeoxyglucose F18; C002854:alovudine