Rostomian A, Madison C, Rabinovici G, Jagust W.
Early 11C-PIB frames and 18F-FDG measures are comparable.
Human Amyloid Imaging 2011 Meeting Abstracts. 2011 Jan 15;
Despite the availability of amyloid imaging, physiological information in the form of perfusion and metabolism may
still be useful in dementia evaluations. In this study we investigated whether early 11C-PIB PET frames (perfusion,
pPIB) can provide information equivalent to blood flow and metabolism by assessing the similarity of pPIB and
18F-FDG PET images in patients with AD and FTLD.
Methods: To identify the 11C-PIB frames best representing perfusion, an iterative algorithm was run on the test
cohort with various diagnoses (N = 10) that created pPIB images across multiple frame ranges and calculated
Pearson R values for these frame ranges in comparison to FDG images. Once this perfusion frame range was
determined on the test cohort, it was validated on an extended cohort of AD patients (N = 42) and FTLD patients
(N = 31). pPIB diagnosis was then compared to 18F-FDG diagnosis by performing a logistic regression of regional
tracer measures (pPIB or 18F-FDG) versus diagnosis.
Results: Minutes 1-8 produced the highest voxel-wise correlation between 18F-FDG and pPIB (R = 0.78}0.05). This
pPIB frame range was further validated on the extended AD and FTLD cohort across 12 ROIs (R = 0.91}0.09). A
logistic model using pPIB was able to classify 90.5% of the AD and 83.9% of the FTLD patients correctly. Using
18F-FDG, 88.1% of AD and 83.9% of FTLD patients were classified correctly. The temporal pole and the temporal
neocortex were significant discriminators (p Conclusions: Early PIB frames and 18F-FDG provide similar diagnostic information and are similarly associated
with dementia severity. This could be a useful approach, obviating the need for 18F-FDG scans when longer-lived
amyloid imaging agents become available.