Non-invasive quantification of the amyloid-load is of paramount interest in the field of Alzheimerŕs disease research. We present a combined PET/7 T-MRI and 16.4 T-microscopic-MRI (µMRI) dual-modality imaging approach enabling the quantification of the amyloid-load at high-sensitivity and high-resolution, and of regional cerebral blood flow (rCBF) in the brain of transgenic APP23 mice. Moreover, we demonstrate a novel, voxel-based correlative data analysis method which we used for in-depth evaluation of amyloid-PET and rCBF-data.

 

METHODS:

 

We injected [11C]PIB intravenously in transgenic (tg) and control (co) APP23 mice and performed dynamic PET measurements. rCBF-data were recorded with a flow sensitive alternating inversion recovery (FAIR) approach at 7 T. Subsequently, animals were sacrificed and brains harvested for ex vivo µMRI at 16.4 T with a T2*-weighted gradient-echo sequence at 30 µm spatial resolution. Additionally, correlative amyloid histology was performed. The [11C]PIB-PET data were quantified to non-displaceable binding potentials (BPnd) using the Logan graphical analysis; FAIR-data were quantified with a simplified version of the Bloch equation.

 

 

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