title: A phantom approach to interscanner comparability of computed tomographic brain perfusion parameters.
abstract: OBJECTIVE
  This study aimed to create a phantom, which allows reproducible computed tomography perfusion experiments, and to identify the influence of contrast bolus configuration, scan parameters, and scanner hardware on the calculation of perfusion parameters.
  
  
  METHODS
  A discoid perfusion phantom with centrifugally directed flow was constructed. Brain parenchyma was simulated by inert polyoxymethylene spheres. Repeated measurements were performed with variations of the above-mentioned factors, and their effects on perfusion results were analyzed.
  
  
  RESULTS
  Calculated flow values measured during experiments were reproducible and showed good correlation with the true flow (R = 0.995, P < 0.01). Tube voltage, injection rate of the contrast agent, the mathematical perfusion algorithm, and the hardware of the scanner hardware had a reproducible influence on calculated perfusion results.
  
  
  CONCLUSIONS
  In the long term, perfusion phantoms might be helpful in identifying hardware-specific and protocol-related factors of different computed tomography scanners to improve comparability of different scanners and scanning protocols.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany. mathys@uni-duesseldorf.de
authors.forename: Christian
authors.initials: C
authors.lastname: Mathys
authors.forename: Konrad
authors.initials: K
authors.lastname: Rybacki
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Wittsack
authors.forename: Rotem Shlomo
authors.initials: RS
authors.lastname: Lanzman
authors.forename: Falk Roland
authors.initials: FR
authors.lastname: Miese
authors.forename: Stephan
authors.initials: S
authors.lastname: Macht
authors.forename: Sven
authors.initials: S
authors.lastname: Eicker
authors.forename: Gerd
authors.initials: G
authors.lastname: Meyer zu Hörste
authors.forename: Gerald
authors.initials: G
authors.lastname: Antoch
authors.forename: Bernd
authors.initials: B
authors.lastname: Turowski
mesh_terms: D000465:Algorithms; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply*; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D036542:Tomography, Spiral Computed / Q000295:instrumentation; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*
chemical_list: D003287:Contrast Media