Data Documentation for PET Imaging Freeze (MK6240)

Freeze:

This documentation pertains to the Freeze 2025_May of the longitudinal PET data (18FMK6240) for the ADRC & WRAP cohorts, as collected by the Wisconsin Alzheimer's Disease Research Center.

Counts:

This imaging dataset includes 1142 MK6240 scans on 739 participants (200 ADRC; 507 WRAP).

There are 1135 MK6240 SUVR results on 738 participants (208 ADRC; 530 WRAP; 421 with one scan, 247 with two scans, 61 with three scans, and 9 with four+ scans; 500 female; 81 URG; 62 MCI and 10 Dementia at first visit; 78 MCI and 14 Dementia at last visit; < 5 participant(s) are aged 90+, of those not: mean first and last ages of 67.3 and 68.6, respectively; mean first and last days since baseline of 4017 and 4526, respectively).

All of the above applies to MK6240 visual rating results.

Per data sharing agreements with the Oneida nation, data from Native American participants are not included in this dataset.

STRUCTURE:
Subdirectories are arranged as follows:

sub-<subject label>/
    ses-<session label>/
        anat/
            sub-<subject label>_ses-<session label>_T1w.nii.gz          #T1-weighted MRI
        pet/
            sub-<subject label>_ses-<session label>_trc-18FMK6240.nii.gz         # PET data
            sub-<subject label>_ses-<session label>_trc-18FMK6240.json         # JSON describing DTI
derivatives/
    mk6240_suvr/
        mk6240_suvr_aal.tsv         # combined MK6240 SUVR ROI-level values - aal atlas
        mk6240_suvr_homic.tsv         # combined MK6240 SUVR ROI-level values - homic atlas
        mk6240_suvr_long.tsv         # combined MK6240 SUVR ROI-level values - all atlases in long format
        mk6240_suvr_morimod.tsv         # combined MK6240 SUVR ROI-level values - morimod atlas

    visual_rating/
        mk6240_visual_ratings.tsv         # combined MK6240 visual rating

<subject label> represents the subject's study identifier.
<session label> represents the subject's integer age at the time of the PET scan.

DERIVED VARIABLES:

Within mk6240_suvr_homic.tsv

• suvr_mtc: meta-temporal composite ROI (ROIs: entorhinal cortex, amygdala, parahippocampal gyrus, fusiform gyrus, inferior and middle temporal gyri)
• suvr_mtl: medial temporal lobe ROI (ROIs: amygdala, hippocampus, parahippocampal gyrus)
• suvr_itg: inferior temporal gyrus ROI (Regions: anterior, posterior, and temporo-occipital)

Within mk6240_visual_ratings.tsv

• mk_vr_mtl: MK6240 visual rating indicator of signal in Braak stage 1 AND 2
• mk_vr_neo: MK6240 visual rating indicator of signal in Braak stage 3, 4, 5, OR 6.
• mk_vr: MK6240 summed visual rating by Braak staging

REFERENCES:

Papers describing the construction of the SUVR meta-temporal composite (suvr_mtc):

Jack CR Jr, Wiste HJ, Weigand SD, et al. Defining imaging biomarker cut points for brain aging and Alzheimer's disease. Alzheimers Dement. 2017;13(3):205-216. https://doi.org/doi:10.1016/j.jalz.2016.08.005.

Cody KA, Langhough RE, Zammit MD, et al. Characterizing brain tau and cognitive decline along the amyloid timeline in Alzheimer's disease. Brain. 2024;147(6):2144-2157. https://doi.org/doi:10.1093/brain/awae116.

Papers describing the construction of the visual read (mk_vr):

Shuping JL, Matthews DC, Adamczuk K, et al. Development, initial validation, and application of a visual read method for [18F]MK-6240 tau PET. Alzheimers Dement (N Y). 2023;9(1):e12372. Published 2023 Feb 12. https://doi.org/doi:10.1002/trc2.12372. 

Rea Reyes RE, Cody KA, Wilson RE, et al. Visual read of [F-18]florquinitau PET that includes and extends beyond the mesial temporal lobe is associated with increased plasma pTau217 and cognitive decline in a cohort that is enriched with risk for Alzheimer's disease. Alzheimers Dement. Published online November 19, 2024. https://doi.org/doi:10.1002/alz.14406. 

Funding/Acknowledgments:

Papers including data obtained from these images should acknowledge NIH R01 AG027161 (the Wisconsin Registry for Alzheimer's Prevention) and/or NIH P30 AG062715 (the Wisconsin Alzheimer's Disease Research Center).

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