Cohen AD, Price JC, Mathis CA, Nebes RD, Saxton JA, Snitz BE, Aizenstein HJ, Weissfeld LA, DeKosky ST, Klunk WE.
Longitudinal changes in fibrillar amyloid-beta deposition across the cognitive spectrum.
Human Amyloid Imaging 2011 Meeting Abstracts. 2011 Jan 15;
Background: Studies of As show variations in As load across cognitive states. It is clear there are time-dependent
increases in As through progression from amyloid-free to AD-like As levels. In-vivo amyloid imaging allows an
opportunity to follow As deposition within individuals over time. Here, we determined changes in As over time in
normal controls (NC), Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD).
Methods: Longitudinal changes were measured in 55 NC [44% PiB(+)], 27 MCI [74%PiB(+)] and 15 AD [100%
PiB(+)] over 1-3yrs and compared to those in six-AD, 7-NC, 9-MCI subjects with two PiB scans (40-60min after
tracer injection) within 28d for test-retest variability. Tissue ratios were calculated for cortical regions-of-interest
(ROI) and normalized to cerebellum (SUVR). The delta-SUVR [(follow-up)-(baseline)] was calculated.
Results: Test-retest variability was -0.001}0.14 SUVR. Increases above 1.645 standard deviations in any ROI
were defined as significant (p