Anatomy, MR, Imaging sequences, Dementia
E. Tuzzi, G. E. Hagberg, D. Balla, J. Loureiro, M. Neumann, C. Laske, R. Pohmann, K. Scheffler; Tübingen/DE
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 isotropic: FOV=50 x 37.45 x 25.6mm3,
matrix= 1000x749x512 in the sagittal plane and FA= 10°; 37 micron isotropic resolution: TR=42.65 ms,
total scan time=54h and 24min) were also acquired on the same frontal cortex area of two post mortem samples from AD and HS respectively,
Quantitative R2* and susceptibility maps were obtained using NumART2* and iLSQR-method respectively,
both in-vivo and ex-vivo.
Background removal and generation of tissue field were achieved using RESHARP algorithm in-vivo and RESHARP,
VSHARP and HARPERELLA algorithms ex-vivo.
Ex-vivo MR images were also registered to a Congo-red histological stain,
Beta-Amyloid detection within the cortex was also estimated at the three spatial resolutions ex-vivo,
by calculating the fraction of paramagnetic spots in QSM and the plaques load in histology at different cutoff.