In-vivo and ex-vivo beta-amyloid load detection in Alzheimer’s Disease using R2* and quantitative susceptibility mapping (QSM) at ultra-high magnetic field: comparison to histology

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. In-vivo, Beta-Amyloid deposits are currently detec[...] 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, TA=9min, FOV=192x174x70.4mm3, matrix size=512x464x88) [...] Results: 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 pp[...] Conclusion: 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