title: Calibration of gamma camera systems for a multicentre European ¹²³I-FP-CIT SPECT normal database.
abstract: OBJECTIVE
  A joint initiative of the European Association of Nuclear Medicine (EANM) Neuroimaging Committee and EANM Research Ltd. aimed to generate a European database of [(123)I]FP-CIT single photon emission computed tomography (SPECT) scans of healthy controls. This study describes the characterization and harmonization of the imaging equipment of the institutions involved.
  
  
  METHODS
  (123)I SPECT images of a striatal phantom filled with striatal to background ratios between 10:1 and 1:1 were acquired on all the gamma cameras with absolute ratios measured from aliquots. The images were reconstructed by a core lab using ordered subset expectation maximization (OSEM) without corrections (NC), with attenuation correction only (AC) and additional scatter and septal penetration correction (ACSC) using the triple energy window method. A quantitative parameter, the simulated specific binding ratio (sSBR), was measured using the "Southampton" methodology that accounts for the partial volume effect and compared against the actual values obtained from the aliquots. Camera-specific recovery coefficients were derived from linear regression and the error of the measurements was evaluated using the coefficient of variation (COV).
  
  
  RESULTS
  The relationship between measured and actual sSBRs was linear across all systems. Variability was observed between different manufacturers and, to a lesser extent, between cameras of the same type. The NC and AC measurements were found to underestimate systematically the actual sSBRs, while the ACSC measurements resulted in recovery coefficients close to 100% for all cameras (AC range 69-89%, ACSC range 87-116%). The COV improved from 46% (NC) to 32% (AC) and to 14% (ACSC) (p < 0.001).
  
  
  CONCLUSIONS
  A satisfactory linear response was observed across all cameras. Quantitative measurements depend upon the characteristics of the SPECT systems and their calibration is a necessary prerequisite for data pooling. Together with accounting for partial volume, the correction for scatter and septal penetration is essential for accurate quantification.
authors.affiliation: Department of Medical Physics and Bioengineering, Southampton University Hospitals NHS Trust, Tremona Road, Southampton SO16 6YD, UK. livia.bolt@suht.swest.nhs.uk
authors.forename: Livia
authors.initials: L
authors.lastname: Tossici-Bolt
authors.forename: John C
authors.initials: JC
authors.lastname: Dickson
authors.forename: Terez
authors.initials: T
authors.lastname: Sera
authors.forename: Robin
authors.initials: R
authors.lastname: de Nijs
authors.forename: Maria Claudia
authors.initials: MC
authors.lastname: Bagnara
authors.forename: Catherine
authors.initials: C
authors.lastname: Jonsson
authors.forename: Egon
authors.initials: E
authors.lastname: Scheepers
authors.forename: Felicia
authors.initials: F
authors.lastname: Zito
authors.forename: Anita
authors.initials: A
authors.lastname: Seese
authors.forename: Pierre Malick
authors.initials: PM
authors.lastname: Koulibaly
authors.forename: Ozlem L
authors.initials: OL
authors.lastname: Kapucu
authors.forename: Michel
authors.initials: M
authors.lastname: Koole
authors.forename: Maria
authors.initials: M
authors.lastname: Raith
authors.forename: Jean
authors.initials: J
authors.lastname: George
authors.forename: Markus Nowak
authors.initials: MN
authors.lastname: Lonsdale
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Münzing
authors.forename: Klaus
authors.initials: K
authors.lastname: Tatsch
authors.forename: Andrea
authors.initials: A
authors.lastname: Varrone
mesh_terms: D002138:Calibration; D016208:Databases, Factual; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D005060:Europe; D015902:Gamma Cameras / Q000592:standards*; D006801:Humans; D012015:Reference Standards; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation* / Q000592:standards*; D014326:Tropanes
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane