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Transient Anomalous diffusion γ metrics can detect iron accumulation in normal brain aging M.
1,5 Guerreri ,
A.
1,5 Caporale ,
M.
2 Palombo ,
E.
3 Macaluso ,
4 Bozzali ,
M.
S.
5 Capuani
1Rome,IT,Sapienza,Department
of anatomical, histological, forensic and of the locomotor system science, 2London,GB,Universiti College of London,CIMIC, 3Lyon,FR,Lyon Neuroscience Research Center,ImpAct Team, 4Rome,IT,Santa Lucia Foundation,Neuroimaging Laboratory, 5Rome,IT,CNR ISC UOS,Physics
Results
Introduction Brain is a complex system undergoing modifications, on different scales, during the entire lifespan. Moreover, iron deposition in subcortical grey matter has been observed in elderly subjects1-3. Recently, we suggested that the γ parameter evaluated using a transient anomalous diffusion (tAD) model depends on both water multicompartmentalization and magnetic susceptibility mismatch (DX) at the interface of different tissue or due to the presence of heavy metals4. In this work we investigated the potential of tAD metrics in detecting microstructural and physiological changes in brain occurring during normal aging.
Materials and methods 28 volunteers, age range 21-77y ( 16-male and 12female, mean±SD=43,8±16,6y) underwent MRI examination performed at 3.0T. R2* was derived as 1/T2*using GE-EPI with TEs=(10,20,35,55)ms, TR=5s, FlipAngle=90°. tAD-metrics (Mean-γ (Mγ), γ-Anisotropy (γA), γ//,γ┴) were obtained5-7 using diffusion weighted acquisitions (Double-SpinEcho-EPI, TR/TE=6400ms/107ms; Δ/δ=72ms/35ms; bandwidth=1860Hz/px; matrix size=128x128, number of axial slices=32; in-plane resolution 1.8x1.8mm2; slice thickness=3mm; NSA=2; 15 non-collinear directions; bvalues=0,200,400,600,800,1000,1500,2000,2500,30 00,4000,5000s/mm2). Moreover, DTI metrics (MD, FA, D//, D┴) were calculated in the b-values range 0-1500s/mm2. We selected 10 gray matter SubCortical nuclei (SC-GM) and 9 White-Matter (WM) regions (Fig.1). Pearson’s correlation test with Bonferroni8 correction was performed between tAD, DTI, R2* metrics and subjects’ age.
Figure.3 ROIs where a significant linear correlation (p
1,5 Guerreri ,
A.
1,5 Caporale ,
M.
2 Palombo ,
E.
3 Macaluso ,
4 Bozzali ,
M.
S.
5 Capuani
1Rome,IT,Sapienza,Department
of anatomical, histological, forensic and of the locomotor system science, 2London,GB,Universiti College of London,CIMIC, 3Lyon,FR,Lyon Neuroscience Research Center,ImpAct Team, 4Rome,IT,Santa Lucia Foundation,Neuroimaging Laboratory, 5Rome,IT,CNR ISC UOS,Physics
Results
Introduction Brain is a complex system undergoing modifications, on different scales, during the entire lifespan. Moreover, iron deposition in subcortical grey matter has been observed in elderly subjects1-3. Recently, we suggested that the γ parameter evaluated using a transient anomalous diffusion (tAD) model depends on both water multicompartmentalization and magnetic susceptibility mismatch (DX) at the interface of different tissue or due to the presence of heavy metals4. In this work we investigated the potential of tAD metrics in detecting microstructural and physiological changes in brain occurring during normal aging.
Materials and methods 28 volunteers, age range 21-77y ( 16-male and 12female, mean±SD=43,8±16,6y) underwent MRI examination performed at 3.0T. R2* was derived as 1/T2*using GE-EPI with TEs=(10,20,35,55)ms, TR=5s, FlipAngle=90°. tAD-metrics (Mean-γ (Mγ), γ-Anisotropy (γA), γ//,γ┴) were obtained5-7 using diffusion weighted acquisitions (Double-SpinEcho-EPI, TR/TE=6400ms/107ms; Δ/δ=72ms/35ms; bandwidth=1860Hz/px; matrix size=128x128, number of axial slices=32; in-plane resolution 1.8x1.8mm2; slice thickness=3mm; NSA=2; 15 non-collinear directions; bvalues=0,200,400,600,800,1000,1500,2000,2500,30 00,4000,5000s/mm2). Moreover, DTI metrics (MD, FA, D//, D┴) were calculated in the b-values range 0-1500s/mm2. We selected 10 gray matter SubCortical nuclei (SC-GM) and 9 White-Matter (WM) regions (Fig.1). Pearson’s correlation test with Bonferroni8 correction was performed between tAD, DTI, R2* metrics and subjects’ age.
Figure.3 ROIs where a significant linear correlation (p
