title: Comparison of HRRT and HR+ scanners for quantitative (R)-[11C]verapamil, [11C]raclopride and [11C]flumazenil brain studies.
abstract: OBJECTIVE
  This study was conducted to directly compare the high-resolution research tomograph (HRRT) (high-resolution brain) and HR+ (standard whole-body) positron emission tomography (PET) only scanners for quantitative brain studies using three tracers with vastly different tracer distributions.
  
  
  METHODS
  Healthy volunteers underwent successive scans on HR+ and HRRT scanners (in random order) using either (R)-[(11)C]verapamil (n = 6), [(11)C]raclopride (n = 7) or [(11)C]flumazenil (n = 7). For all tracers, metabolite-corrected plasma-input functions were generated.
  
  
  RESULTS
  After resolution matching, HRRT-derived kinetic parameter values correlated well with those of HR+ for all tracers (intraclass correlation coefficients ≥0.78), having a good absolute interscanner test-retest variability (≤15 %). However, systematic differences can be seen for HRRT-derived kinetic parameter values (range -13 to +15 %).
  
  
  CONCLUSIONS
  Quantification of kinetic parameters based on plasma-input models leads to comparable results when spatial resolution between HRRT and HR+ data is matched. When using reference-tissue models, differences remain that are likely caused by differences in attenuation and scatter corrections and/or image reconstruction.
authors.affiliation: Department of Radiology & Nuclear Medicine, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands, f.vvelden@vumc.nl.
authors.forename: Floris H P
authors.initials: FH
authors.lastname: van Velden
authors.forename: Syahir M
authors.initials: SM
authors.lastname: Mansor
authors.forename: Daniëlle M E
authors.initials: DM
authors.lastname: van Assema
authors.forename: Bart N M
authors.initials: BN
authors.lastname: van Berckel
authors.forename: Femke E
authors.initials: FE
authors.lastname: Froklage
authors.forename: Shaonan
authors.initials: S
authors.lastname: Wang
authors.forename: Robert C
authors.initials: RC
authors.lastname: Schuit
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Asselin
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Lammertsma
authors.forename: Ronald
authors.initials: R
authors.lastname: Boellaard
authors.forename: Marc C
authors.initials: MC
authors.lastname: Huisman
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging*; D002250:Carbon Radioisotopes / Q000737:chemistry*; D016022:Case-Control Studies; D005442:Flumazenil / Q000008:administration & dosage*; D018757:GABA Modulators / Q000008:administration & dosage; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D049268:Positron-Emission Tomography; D020891:Raclopride / Q000008:administration & dosage; D011868:Radioisotopes / Q000627:therapeutic use; D012016:Reference Values; D015203:Reproducibility of Results; D014018:Tissue Distribution; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed; D014665:Vasodilator Agents / Q000008:administration & dosage; D014700:Verapamil / Q000008:administration & dosage*
chemical_list: D002250:Carbon Radioisotopes; D018757:GABA Modulators; D011868:Radioisotopes; D014665:Vasodilator Agents; D005442:Flumazenil; D020891:Raclopride; D014700:Verapamil