HAI Book 2025 - Flipbook - Page 537
Soleimani-Meigooni, David
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Calibration of multi-site raters for prospective visual read of amyloid
PET scans acquired across the ADRC Consortium for Clarity in ADRD
Research Through Imaging (CLARiTI)
David Soleimani-Meigooni1,2, Ganna Blazhenets1, Renaud La Joie1, Zoe Lin1, Carol Soppe1,
Derek Johnson3, Mary Ellen Koran4, Jonathan McConathy5, Ilya Nasrallah6, Jeremy Tanner7,
Victor Villemagne8, Charles Windon1, Michael Zeineh9, Elizabeth Mormino10, Sterling
Johnson11, Gil Rabinovici1,12
1
Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California, San
Francisco, CA, US
2
Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, US
3
Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN, US
4
Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Phoenix, AZ, US
5
Division of Molecular Imaging and Therapeutics, Department of Radiology, University of Alabama at Birmingham,
Birmingham, AL, US
6
Department of Radiology, University of Pennsylvania, Philadelphia, PA, US
7
Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, University of Texas Health Science Center, San
Antonio, TX, US
8
Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, US
9
Department of Radiology, Stanford University School of Medicine, Stanford, CA, US
10
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, US
11
Wisconsin Alzheimer’s Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, US
12
Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, US
Background: PET visual reads for multi-center studies are conducted centrally by one or a few experts. In
CLARiTI, a broader network of raters will perform the reads, necessitating methods to ensure their accuracy and
reliability.
Methods: All ADRC sites (N=37) will prospectively acquire amyloid PET scans for 800 cognitively unimpaired and
1200 cognitively impaired participants. Each site can use one of four amyloid PET tracers (18F-florbetapir, 18Fflorbetaben, 18F-NAV4694, 11C-PIB). PET scans will be visually interpreted by ten PET neuroimaging experts located
across eight ADRCs, using their preferred hardware, software, and file format (DICOM, NIFTI). Calibration requires
each reader to perform blinded, independent visual interpretation of 180 amyloid PET scans (30 unique and 15
duplicate scans per tracer), previously read and selected by an expert. An even mix of visually non-elevated and
elevated scans were selected, with quantitation spanning -20-120 Centiloids (Figure 1), and 15% were visually
borderline (similar proportion to ADNI4), with quantitation spanning 4-48 Centiloids (mean 21).
Results: Calibration scans were read by a second expert not serving in CLARiTI. There was 97% concordance and
almost perfect agreement between readers (κ=0.932, p
