title: Noninvasive parametric blood flow imaging of head and neck tumours using [15O]H2O and PET/CT.
abstract: OBJECTIVE
  The aim of this study was to develop a simple noninvasive method for measuring blood flow using [15O]H2O PET/CT for the head and neck area applicable in daily clinical practice.
  
  
  METHODS
  Fifteen dynamic [15O]H2O PET emission scans with simultaneous online radioactivity measurements of radial arterial blood [Blood-input functions (IFs)] were performed. Two noninvasively obtained population-based input functions were calculated by averaging all Blood-IF curves corrected for patients' body mass and injected dose [standardized uptake value (SUV)-IF] and for body surface area (BSA-IF) and injected dose. Parametric perfusion images were calculated for each set of IFs using a linearized two-compartment model, and values for several tissues were compared using Blood-IF as the gold standard.
  
  
  RESULTS
  On comparing all tissues, the correlation between blood flow obtained with the invasive Blood-IF and both SUV-IF and BSA-IF was significant (R2=0.785 with P<0.001 and R2=0.813 with P<0.001, respectively). In individual tissues, the performance of the two noninvasive methods was most reliable in resting muscle and slightly less reliable in tumour and cerebellar regions. In these two tissues, only BSA-IF showed a significant correlation with Blood-IF (R2=0.307 with P=0.032 in tumours and R2=0.398 with P<0.007 in the cerebellum).
  
  
  CONCLUSIONS
  The BSA-based noninvasive method enables clinically relevant delineation between areas of low and high blood flow in tumours. The blood flow of low-perfusion tissues can be reliably quantified using either of the evaluated noninvasive methods.
authors.affiliation: Turku PET Centre, Kiinamyllynkatu 4-8, 20521 Turku, Finland. gaber.komar@utu.fi
authors.forename: Gaber
authors.initials: G
authors.lastname: Komar
authors.forename: Vesa
authors.initials: V
authors.lastname: Oikonen
authors.forename: Hannu
authors.initials: H
authors.lastname: Sipilä
authors.forename: Marko
authors.initials: M
authors.lastname: Seppänen
authors.forename: Heikki
authors.initials: H
authors.lastname: Minn
mesh_terms: D000328:Adult; D000368:Aged; D001775:Blood Circulation; D005260:Female; D006258:Head and Neck Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D010104:Oxygen Radioisotopes; D055420:Perfusion Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014867:Water; D055815:Young Adult
chemical_list: D010104:Oxygen Radioisotopes; D014867:Water