Inter-rater variability of visual interpretation and comparison with quantitative evaluation of 11C-PiB PET amyloid images of the Japanese Alzheimer’s Disease Neuroimaging Initiative (J-ADNI) multicenter study

  • Tomohiko Yamane
  • Kenji Ishii
  • Muneyuki Sakata
  • Yasuhiko Ikari
  • Tomoyuki Nishio
  • Kazunari Ishii
  • Takashi Kato
  • Kengo Ito
  • Michio Senda
  • J-ADNI Study Group
Original Article

DOI: 10.1007/s00259-016-3591-2

Cite this article as:
Yamane, T., Ishii, K., Sakata, M. et al. Eur J Nucl Med Mol Imaging (2017) 44: 850. doi:10.1007/s00259-016-3591-2

Abstract

Purpose

The aim of this study was to assess the inter-rater variability of the visual interpretation of 11C-PiB PET images regarding the positivity/negativity of amyloid deposition that were obtained in a multicenter clinical research project, Japanese Alzheimer’s Disease Neuroimaging Initiative (J-ADNI). The results of visual interpretation were also compared with a semi-automatic quantitative analysis using mean cortical standardized uptake value ratio to the cerebellar cortex (mcSUVR).

Methods

A total of 162 11C-PiB PET scans, including 45 mild Alzheimer’s disease, 60 mild cognitive impairment, and 57 normal cognitive control cases that had been acquired as J-ADNI baseline scans were analyzed. Based on visual interpretation by three independent raters followed by consensus read, each case was classified into positive, equivocal, and negative deposition (ternary criteria) and further dichotomized by merging the former two (binary criteria).

Results

Complete agreement of visual interpretation by the three raters was observed for 91.3% of the cases (Cohen κ = 0.88 on average) in ternary criteria and for 92.3% (κ = 0.89) in binary criteria. Cases that were interpreted as visually positive in the consensus read showed significantly higher mcSUVR than those visually negative (2.21 ± 0.37 vs. 1.27 ± 0.09, p < 0.001), and positive or negative decision by visual interpretation was dichotomized by a cut-off value of mcSUVR = 1.5. Significant positive/negative associations were observed between mcSUVR and the number of raters who evaluated as positive (ρ = 0.87, p < 0.0001) and negative (ρ = −0.85, p < 0.0001) interpretation. Cases of disagreement among raters showed generally low mcSUVR.

Conclusions

Inter-rater agreement was almost perfect in 11C-PiB PET scans. Positive or negative decision by visual interpretation was dichotomized by a cut-off value of mcSUVR = 1.5. As some cases of disagreement among raters tended to show low mcSUVR, referring to quantitative method may facilitate correct diagnosis when evaluating images of low amyloid deposition.

Keywords

Amyloid imaging Inter-rater variability Multi-center study 11C-PiB PET Mean cortical SUVR 

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Tomohiko Yamane
    • 1
    • 2
    • 3
    • 4
  • Kenji Ishii
    • 3
    • 4
  • Muneyuki Sakata
    • 3
    • 4
  • Yasuhiko Ikari
    • 2
    • 4
    • 5
  • Tomoyuki Nishio
    • 2
    • 4
    • 5
  • Kazunari Ishii
    • 4
    • 6
  • Takashi Kato
    • 4
    • 7
  • Kengo Ito
    • 4
    • 7
  • Michio Senda
    • 2
    • 4
  • J-ADNI Study Group
  1. 1.Department of Nuclear MedicineSaitama Medical University Saitama International CenterHidakaJapan
  2. 2.Division of Molecular ImagingInstitute of Biomedical Research and InnovationKobeJapan
  3. 3.Team for Neuroimaging ResearchTokyo Metropolitan Institute of GerontologyTokyoJapan
  4. 4.
  5. 5.Research Association for BiotechnologyTokyoJapan
  6. 6.Department of RadiologyKinki University HospitalSayamaJapan
  7. 7.Department of Brain Science and Molecular ImagingNational Center for Geriatrics and GerontologyObuJapan

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