Nikoo Fattahi¹, Arvin Arani¹, Kevin J Glaser¹, Armando Manduca¹, Nicholas M Wetjen², Perry Avital², Richard L Ehman¹, and John Huston III^1
1Radiology, Mayo Clinic, Rochester, Minnesota, United States, ²Neurosurgery, Mayo Clinic, Rochester, Minnesota, United States

MR Elastography using a 3T scanner and shear waves of 60 Hz was performed on patients with normal pressure hydrocephalus. A post-processing technique was applied to calculate brain elasticity that included whole brain as well as lobar stiffness. Results demonstrated an increase in brain stiffness of patients with NPH compared with age and sex matched normal controls.

Qing Wang¹, Yong Wang¹, Joshua S. Shimony¹, Anne M. Fagan², John C. Morris², and Tammie L.S. Benzinger^1,3
1Radiology, Washington University School of Medicine, St. Louis, MO, United States, ²Neurology, Washington University School of Medicine, St. Louis, MO, United States, ³Neurological Surgery, Washington University School of Medicine, St. Louis, MO, United States

Alzheimer disease (AD) affects 20-30 million people worldwide. DTI was utilized on 144 normal participants, 30 and 18 in preclinical stage1 and 2 respectively. DTI radial, axial and mean diffusivities significantly decreased in multiple white matter regions in stage1, and pseudo-normalized at stage 2. One explanation would be an early stage of microglia cell activation after amyloid deposition and BBB disruption and later concurrent involvement of axon damage, cell infiltration and edema. Monte Carlo simulation confirmed DTI findings. This study suggested that advanced diffusion MRI can potentially be used to improve risk stratification and early treatment efficacy for preclinical AD.

Justin M Remer¹, Douglas C Dean III^1,2, Jonathan O'Muircheartaigh³, Sara D'Arpino¹, Holly Dirks¹, and Sean C.L. Deoni^1,4
1Advanced Baby Imaging Lab, School of Engineering, Brown University, Providence, RI, United States, ²Waisman Lab for Brain Imaging and Behavior, University of Wisconsin, Madison, WI, United States, ³Department of Neuroimaging, King's College London, Institute of Psychiatry, London, United Kingdom, ⁴Department of Pediatric Radiology, Children's Hospital Colorado, Aurora, CO, United States

The apolipoprotein (APOE) ε4 allele, a main risk factor for late onset Alzheimer’s Disease, has been associated with neurological differences in infants in cross-sectional studies. Longitudinal myelin growth curves, in 223 infants and children grouped according to APOE genotype, exhibited differential white matter development in neuroanatomical regions related to Alzheimer’s Disease. Group differences in overall cognition were also observed between APOE ε4 carriers and noncarriers. Results suggest the ε4 allele plays an important role in early neurodevelopment, with both anatomical and cognitive brain alterations seen several decades before disease symptoms commonly occur.