title: Cross-camera comparison of ROI-based semi-quantitative ¹²³I-IBZM SPECT data in healthy volunteers using an anthropomorphic phantom for calibration.
abstract: BACKGROUND
  In (123)I-Iolopride (IBZM) SPECT reference values may diverge between camera systems. If multicenter pooling of normal material databases is needed, differences in measured semi-quantitative data due to equipment performance and reconstruction parameters have to be investigated in each instance to determine the comparability.
  
  
  OBJECTIVE
  To explore the differences in (123)I-IBZM measured uptake ratios between two different gamma cameras in healthy controls, the intra-rater reproducibility of the image evaluation method and the possibility to equalize uptake ratios by calibration through an anthropomorphic phantom.
  
  
  METHODS
  Differences in ROI-based semi-quantitative data from two different gamma camera systems, the three-headed brain dedicated Neurocam and the two-headed multipurpose hybrid system Infinia Hawkeye, were studied using image data from a group of healthy volunteers and an anthropomorphic brain-phantom scanned with both cameras. Several reconstruction methods and corrections were applied. To test the reliability of the ROI method, the intra-observer reproducibility was determined for the ROI method in this study.
  
  
  RESULTS
  The ROI method had a high reliability. Differences in mean measured uptake (123)I-IBZM ratios in healthy controls varied between 2.9% and 6.5% depending on reconstruction and correction for attenuation and scatter. After calibration, the differences decreased. There were no statistically significant differences between corrected ratios from the two camera systems in the study when images were reconstructed with attenuation correction.
  
  
  CONCLUSIONS
  The conformity of uptake ratios in attenuation corrected (123)I-IBZM images derived from the two different cameras was improved by using an anthropomorphic phantom for calibration.
authors: Department of Radiation Sciences, Diagnostic Radiology, Umeå University, Umeå susanna.jakobson.mo@diagrad.umu.se.
authors: Susanna Jakobson
authors: SJ
authors: Mo
authors: Department of Radiation Sciences, Radiation Physics, Umeå University, Umeå
authors: Anne
authors: A
authors: Larsson
authors: Department of Radiation Sciences, Radiation Physics, Umeå University, Umeå
authors: Lennart
authors: L
authors: Johansson
authors: Department of Public Health and Clinical Medicine, Epidemiology and Global Health, Umeå University, Umeå, Sweden.
authors: Hans
authors: H
authors: Stenlund
authors: Department of Pharmacology and Clinical Neuroscience, Neurology, Umeå University, Umeå
authors: Lars
authors: L
authors: Forsgren
authors: Department of Radiation Sciences, Diagnostic Radiology, Umeå University, Umeå
authors: Katrine
authors: K
authors: Riklund
mesh_terms: D000368:Aged; D001549:Benzamides / Q000493:pharmacokinetics; D001921:Brain / Q000000981:diagnostic imaging*; D002138:Calibration; D005260:Female; D015902:Gamma Cameras; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D015588:Observer Variation; D019047:Phantoms, Imaging; D011446:Prospective Studies; D011759:Pyrrolidines / Q000493:pharmacokinetics; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation*
chemical_list: D001549:Benzamides; D011759:Pyrrolidines; D019275:Radiopharmaceuticals; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide
keywords: IBZM; Parkinsonian disorders; SPECT; healthy volunteers; imaging phantom; radionuclide imaging