title: Interobserver variability, and visual and quantitative parameters of (123)I-FP-CIT SPECT (DaTSCAN) studies.
abstract: OBJECTIVE
  To evaluate the degree of interobserver agreement in the visual interpretation of (123)I-FP-CIT studies and to investigate for potential associations between visual and semi-quantitative parameters.
  
  
  METHODS
  Eighty-nine (123)I-FP-CIT studies were blindly reviewed by 3 independent observers: a consultant, a resident doctor and a radiographer. They classified every study as either "normal" or "abnormal" and assigned visual (123)I-FP-CIT uptake scores (2: normal, 1: reduced and 0: no uptake) in basal ganglia nuclei (right and left putamina and caudate nuclei) on every scan. Striatal (123)I-FP-CIT binding ratios were calculated using crescent-ROI software. The interobserver agreement for the interpretation of studies and for visual score assignment was evaluated by means of κ statistics. We investigated for associations of binding ratios with visual scores and clinical parameters; patients' clinical diagnoses served as the reference standard.
  
  
  RESULTS
  There was excellent interobserver agreement (κ 0.89-0.93) in classifying studies as "normal" or "abnormal" and fine agreement in assignment of visual scores (κ 0.71-0.80 for putamina and 0.50-0.79 for caudate nuclei). Nuclei with scores of 1 and 0 showed significantly reduced binding ratios (about 30 and 50%, respectively) compared with the nuclei scored as 2. ROC analysis indicated the optimal cutoff point of striatal binding ratio at 3.8 (sensitivity 98.5%, specificity 95%) for the detection of parkinsonian syndromes. Striatal binding ratios were negatively associated with age in normal subjects and disease duration in Parkinson's disease patients.
  
  
  CONCLUSIONS
  Visual interpretation of (123)I-FP-CIT studies showed very good interobserver agreement. We found significant associations among visual, semi-quantitative and clinical parameters.
authors.affiliation: Nuclear Medicine Department, "Evaggelismos" General Hospital, Athens, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Papathanasiou
authors.forename: Phivi
authors.initials: P
authors.lastname: Rondogianni
authors.forename: Panagiota
authors.initials: P
authors.lastname: Chroni
authors.forename: Marios
authors.initials: M
authors.lastname: Themistocleous
authors.forename: Efstathios
authors.initials: E
authors.lastname: Boviatsis
authors.forename: Xanthi
authors.initials: X
authors.lastname: Pedeli
authors.forename: Damianos
authors.initials: D
authors.lastname: Sakas
authors.forename: Ioannis
authors.initials: I
authors.lastname: Datseris
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002421:Caudate Nucleus / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014326:Tropanes
chemical_list: D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane