Abstract
The β-amyloid radiotracer [(18)F]NAV4694 is a desirable alternative to [(11)C]PiB, possessing similar imaging characteristics and favorable radiopharmaceutical distribution. This work examined the consistency of amyloid measures between [(11)C]PiB and [(18)F]NAV4694 as participants transition between radiotracers in longitudinal studies. Thirty-five participants with ≥1 [(11)C]PiB scans, followed by a [(18)F]NAV4694 scan, were recruited from ongoing AD studies at the University of Wisconsin. Amyloid stability was evaluated in Aβ- individuals and amyloid accumulation was evaluated in Aβ+ individuals. In Aβ- participants, [(18)F]NAV4694 measures were consistent with the preceding [(11)C]PiB measures, showing no significant differences in CL values. Aβ+ participants exhibited an average annualized Aβ accumulation of 6.0 ± 1.8 CL/yr, consistent with modeled [(11)C]PiB Aβ projected outcomes. [(18)F]NAV4694 demonstrated both consistency in trending amyloid accumulation and constancy in sustained Aβ- participants compared with [(11)C]PiB. This study highlights how both radiotracers can be integrated within a single analytical framework under a uniform processing pipeline.