title: Global scaling for semi-quantitative analysis in FP-CIT SPECT.
abstract: Semi-quantitative characterization of dopamine transporter availability from single photon emission computed tomography (SPECT) with 123I-ioflupane (FP-CIT) is based on uptake ratios relative to a reference region. The aim of this study was to evaluate the whole brain as reference region for semi-quantitative analysis of FP-CIT SPECT. The rationale was that this might reduce statistical noise associated with the estimation of non-displaceable FP-CIT uptake.
  
  
  METHODS
  150 FP-CIT SPECTs were categorized as neurodegenerative or non-neurodegenerative by an expert. Semi-quantitative analysis of specific binding ratios (SBR) was performed with a custom-made tool based on the Statistical Parametric Mapping software package using predefined regions of interest (ROIs) in the anatomical space of the Montreal Neurological Institute. The following reference regions were compared: predefined ROIs for frontal and occipital lobe and whole brain (without striata, thalamus and brainstem). Tracer uptake in the reference region was characterized by the mean, median or 75th percentile of its voxel intensities. The area (AUC) under the receiver operating characteristic curve was used as performance measure.
  
  
  RESULTS
  The highest AUC of 0.973 was achieved by the SBR of the putamen with the 75th percentile in the whole brain as reference. The lowest AUC for the putamen SBR of 0.937 was obtained with the mean in the frontal lobe as reference.
  
  
  CONCLUSIONS
  We recommend the 75th percentile in the whole brain as reference for semi-quantitative analysis in FP-CIT SPECT. This combination provided the best agreement of the semi-quantitative analysis with visual evaluation of the SPECT images by an expert and, therefore, is appropriate to support less experienced physicians.
authors.forename: D
authors.initials: D
authors.lastname: Kupitz
authors.forename: I
authors.initials: I
authors.lastname: Apostolova
authors.forename: C
authors.initials: C
authors.lastname: Lange
authors.forename: G
authors.initials: G
authors.lastname: Ulrich
authors.forename: H
authors.initials: H
authors.lastname: Amthauer
authors.forename: W
authors.initials: W
authors.lastname: Brenner
authors.affiliation: Ralph Buchert, PhD, Charité - Universitätsmedizin Berlin, Department of Nuclear Medicine, Charitéplatz 1, 10117 Berlin, Germany, Tel. +49/(0)30/450 62 70 59, Fax +49/(0)30/45 07 52 79 59.
authors.forename: R
authors.initials: R
authors.lastname: Buchert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D003198:Computer Simulation; D003937:Diagnosis, Differential; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008875:Middle Aged; D008954:Models, Biological; D057054:Molecular Imaging / Q000379:methods; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging / Q000378:metabolism*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014326:Tropanes / Q000493:pharmacokinetics*
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D019275:Radiopharmaceuticals; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane
keywords: 123I-ioflupane; DaTSCAN; Dopamine transporter scintigraphy; FP-CIT; global scaling; reference region; semi-quantitative analysis