HAI Book 2025 - Flipbook - Page 72
Blazhenets, Ganna
Every Centiloid, from everywhere, all at once
Ganna Blazhenets1, David Soleimani-Meigooni1, Heather Snyder2, Ioannis Pappas3, Cally Xiao3,
Arthur W. Toga3, Christina B. Young4, Reisa A. Sperling5, Susan M. Landau6, Michael Weiner1,
Raquel C. Gardner7, William J. Jagust6, Pierrick Bourgeat8, Christopher C. Rowe8, Colin L.
Masters8, Gill Farrar9, Mahnaz Shekari10, Lyduine E. Collij11,12, Ruben Smith11, Oskar Hansson11,
Gaël Chételat13, Victor L. Villemagne14, Brian Lopresti14, Yishu Chao6, Theresa M. Harrison6, Sid
E. O9Bryant15, Meredith N. Braskie16, Andrew March17, Robert A. Koeppe18, Maria C. Carrillo2,
Bradford C. Dickerson5, Liana G. Apostolova19, Christopher G. Schwarz20, Prashanthi Vemuri20,
Val J. Lowe20, Elizabeth C. Mormino4, Gil D. Rabinovici1, Renaud La Joie1
1
Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, US
Alzheimer’s Association, Chicago, IL, US
3
Laboratory of Neuro Imaging, USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC,
University of Southern California, Los Angeles, CA, US
4
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, US
5
Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, US
6
Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, US
7
Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat Gan, IL
8
Florey Institute of Neurosciences and Mental Health, University of Melbourne, Melbourne, AU
9
GE Healthcare Life Sciences, Amersham, GB
10
Barcelonaβeta Brain Research Center (BBRC), Pasqual Maragall Foundation, Barcelona, ES
11
Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Faculty of Medicine, Lund University, Lund,
SE
12
Department of Radiology and Nuclear Medicine, Amsterdam UMC, location VUmc, Amsterdam, NL
13
Normandie Université, Université de Caen, Institut National de la Santé et de la Recherche Médicale, Unité 1237,
Groupement d’Intérêt Public Cyceron, Caen, FR
14
Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, US
15
Institute for Translational Research, University of North Texas Health Science Center, Fort Worth, TX, US
16
Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA,
US
17
American College of Radiology, Philadelphia, PA, US
18
University of Michigan, Ann Arbor, MI, US
19
Indiana University School of Medicine, Indianapolis, IN, US
20
Department of Radiology, Mayo Clinic, Rochester, MN, US
2
Background: Ten years after the original publication, the Centiloid framework is now broadly used to harmonize
amyloid-PET quantification, facilitate data sharing, and allow direct comparison across cohorts. We evaluated the
global implementation of Centiloids by comparing their distribution and corresponding positivity thresholds
across cohorts.
Methods: We gathered data from publicly available cohorts and reached out to investigators across the world to
collect cross-sectional Centiloids, demographic, clinical, and visual read data. Gaussian mixture models (GMM)
were fitted to Centiloid values for each cohort and cutoffs were calculated as mean + 2SD of the first Gaussian.
When visual reads were available, we determined Centiloid cutoffs that maximized i) correspondence with visual
read (Cohen9s kappa) and ii) sensitivity and specificity in ROC analysis (Youden9s index). Data was combined across
cohorts using meta-analyses.
HAI2025 - 72
