Comparison of dual-biomarker PIB-PET and dual-tracer PET in AD diagnosis

Objectives To identify the optimal time window for capturing perfusion information from early 11 C-PIB imaging frames (perfusion PIB, 11 C-pPIB) and to compare the performance of 18 F-FDG PET and "dual biomarker" 11 C-PIB PET [ 11 C-pPIB and amyloid PIB ( 11 C-aPIB)] for classification of AD, MCI and CN subjects. Methods Forty subjects (14 CN, 12 MCI and 14 AD patients) underwent 18 F-FDG and 11 C-PIB PET studies. Pearson correlation between the 18 F-FDG image and sum of early 11 C-PIB frames was maximised to identify the optimal time window for 11 C-pPIB. The classification power of imaging parameters was evaluated with a leave-one-out validation. Results A 7-min time window yielded the highest correlation between 18 F-FDG and 11 C-pPIB. 11 C-pPIB and 18 F-FDG images shared a similar radioactive distribution pattern. 18 F-FDG performed better than 11 C-pPIB for the classification of both AD vs. CN and MCI vs. CN. 11 C-pPIB + 11 C-aPIB and 18 F-FDG + 11 C-aPIB yielded the highest classification accuracy for the classification of AD vs. CN, and 18 F-FDG + 11 C-aPIB had the best classification performance for the classification of MCI vs. CN. Conclusion C-pPIB could serve as a useful biomarker of rCBF for measuring neural activity and improve the diagnostic power of PET for AD in conjunction with 11 C-aPIB. 18 F-FDG and 11 C-PIB dual-tracer PET examination could better detect MCI. Key Points • Dual-tracer PET examination provides neurofunctional and neuropathological information for AD diagnosis. • The identified optimal 11C-pPIB time frames had highest correlation with 18F-FDG. • 11C-pPIB images shared a similar radioactive distribution pattern with 18F-FDG images. • 11C-pPIB can provide neurofunctional information. • Dual-tracer PET examination could better detect MCI.