Aims and objectives
Alzheimer’s Disease (AD) is the most common cause of dementia worldwide.
So far univocal diagnosis of AD is only achieved by postmortem histology.
Beta-Amyloid plaques are known to be classical hallmarks of the post mortem Alzheimer´s Disease brain.
Beta-Amyloid deposits are currently detected by PiB-PET imaging,
which only provides a coarse localization of the affected areas.
On the other hand,
ultra-high field (UHF) MRI offers a potential non-invasive means to diagnose AD in early stage by allowing imaging at very high spatial resolution.
Methods and materials
Two patients with autosomal dominant AD (female 51y,
male 35y) and two age and sex-matched healthy subjects (HS) were scanned at 9.4T using a multi-echo (N=5) 3D-GRE sequence (0.375x0.375x0.8mm3 voxel size,
TR=35ms; TE=6 to 30ms in steps of 6ms,
matrix size=512x464x88) and a high resolution 3DGRE weighted sequence (AWI),
(0.130x0.130x0.6mm3 voxel size,
A multi-echo (N=3) GRE sequence (100μm isotropic voxels,
TA=2.3h) and a 3D GRE sequences at two very high spatial resolutions (50 micron...
A variation of 70ms-1ca.
in the effective transverse relaxation rate was observed between grey and white matter in AD patient compared to healthy subject (Figure 1).
A pattern between grey and white matter,
corresponding to paramagnetic effects,
was also detected in the susceptibility map (0-0.04 ppm) of the AD patient with respect to the healthy subject (Figure 1).
the spatial resolution reached in-vivo was not sufficient to reveal microstructure of the cortical layers at higher level of detail.
Ex-vivo R2* maps showed the same...
Both R2* and QSM methods at ultra-high field hold promise for detecting Beta-Amyloid load within the cortical rim providing a potential means for early diagnosis of AD in-vivo.
Optimization of the QSM algorithm would likely increase the power of Beta-Amyloid detection ex-vivo and in-vivo.
High Field Magnetic Resonance,
Max Planck Institute for Biological Cybernetics,
Fax: + 31503617008
de Ronde FM,
van Duinen SG,Webb AG,
van Buchem MA,
van der Weerd L.
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