RT Journal Article SR Electronic T1 Interrater variability of image interpretation for 18F-FDG and 11C-PIB PET in the diagnosis of Alzheimer’s disease JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1259 OP 1259 VO 52 IS supplement 1 A1 Tomohiko Yamane A1 Hidehito Nagai A1 Tomoyuki Nishio A1 Yasuhiko Ikari A1 Yoko Makishi A1 Kazunari Ishii A1 Kenji Ishii A1 Takashi Kato A1 Kengo Ito A1 Michio Senda YR 2011 UL http://jnm.snmjournals.org/content/52/supplement_1/1259.abstract AB 1259 Objectives The aim of this study was to evaluate the interrater variability and usefulness of consensus reading for FDG and PIB PET regarding the diagnosis of Alzheimer’s disease (AD). Methods We analyzed 255 FDG and 122 PIB PET obtained in 23 centers as initial baseline scans of Japanese Alzheimer’s Disease Neuroimaging Initiative (J-ADNI) project. Initially, these PET scans were independently interpreted visually by 3 expert raters blinded to the clinical diagnosis. Subsequently, final decisions were made by a consensus of the raters. In FDG PET interpretation, Silverman’s criterion was used for classifying the uptake pattern into 7 categories (Silverman DH, et al. JAMA. 2001; FDG-7), and further into 2 categories: progressive and non-progressive pattern (FDG-2). In PIB PET interpretation, the scans were classified into 3 categories: negative, equivocal and positive amyloid deposition (PIB-3). Concordance among the 3 raters was evaluated by Cohen Κ statistics. Results Complete concordance rates among 3 raters were 61.1% in FDG-7, 75.3% in FDG-2 and 92.6% in PIB-3. Concordance of 2 or 3 out of the 3 raters was 94.1% in FDG-7 and 97.5% in PIB-3. With respect to FDG, concordance rates between clinical diagnosis and PET diagnosis in consensus reading were higher than those in individual reading (49.4% vs 44.9-47.8% in FDG-7, and 52.6% vs 49.4-51.0% in FDG-2). In PIB-3, the concordance rate in consensus reading was not the highest (50.8% vs 49.2-52.5%). Average Κ values were 0.56 in FDG-7, 0.66 in FDG-2 and 0.89 in PIB-3. Conclusions Interrater variability was minimal for PIB PET but was significant for FDG PET, for which a consensus reading is valuable in the diagnosis of AD. Research Support Research Association for Biotechnology (J-ADNI project