Our objective was to determine the optimal approach for assessing amyloid disease in a cognitively normal elderly population. Methods: Dynamic 18F-flutemetamol PET scans were acquired using a coffeebreak protocol (a 0- to 30-min scan and a 90- to 110-min scan) on 190 cognitively normal elderly individuals (mean age, 70.4 y; 60% female). Parametric images were generated from SUV ratio (SUVr) and nondisplaceable binding potential (BPND) methods, with cerebellar gray matter as a reference region, and were visually assessed by 3 trained readers. Interreader agreement was calculated using κ-statistics, and semiquantitative values were obtained. Global cutoffs were calculated for both SUVr and BPND using a receiver-operating-characteristic analysis and the Youden index. Visual assessment was related to semiquantitative classifications. Results: Interreader agreement in visual assessment was moderate for SUVr (κ 5 0.57) and good for BPND images (κ 5 0.77). There was discordance between readers for 35 cases (18%) using SUVr and for 15 cases (8%) using BPND, with 9 overlapping cases. For the total cohort, the mean (±SD) SUVr and BPND were 1.33 (±0.21) and 0.16 (±0.12), respectively. Most of the 35 cases (91%) for which SUVr image assessment was discordant between readers were classified as negative based on semiquantitative measurements. Conclusion: The use of parametric BPND images for visual assessment of 18F-flutemetamol in a population with low amyloid burden improves interreader agreement. Implementing semiquantification in addition to visual assessment of SUVr images can reduce false-positive classification in this population.

Additional Metadata
Keywords 18F-flutemetamol PET, amyloid pathology, visual assessment, preclinical Alzheimer disease
Persistent URL dx.doi.org/10.2967/jnumed.118.211532, hdl.handle.net/1765/116182
Journal The Journal of Nuclear Medicine
Citation
Collij, L.E., Konijnenberg, E., Reimand, J, ten Kate, M.T, den Braber, A, Alves, I.L., … van Berckel, B. N. M. (2018). Assessing Amyloid Pathology in Cognitively Normal Subjects Using F-18-Flutemetamol PET: Comparing Visual Reads and Quantitative Methods. The Journal of Nuclear Medicine, 60(4), 541–547. doi:10.2967/jnumed.118.211532