Master of Science in Biomedical Engineering (MSBME), Wright State University, 2023, Biomedical Engineering

Alzheimer's disease (AD) is the seventh leading cause of death globally with an estimated 6.5 million Americans aged 65 and above living with Alzheimer's dementia in 2022 and at a projected national cost of $321 billion. AD is characterized by a progressive and irreversible neurodegenerative dysfunction with clinical symptoms such as deterioration in cognition and memory loss. The Alzheimer's Disease Neuroimaging Initiative (ADNI) is a multi-site, public-private global research initiative that supports both investigation and development of treatments that slow or terminate AD progression. The study included 60 participants, comprising 30 AD and 30 control cohorts respectively. All participants were from the ADNI 1 group with a recorded Functional Activities Questionnaire (FAQ.) and Neuropsychiatric Inventory Questionnaire (NPI-Q) score. Gray matter volumetric alterations detected from magnetic resonance image (MRI) scans have been validated as a crucial AD biomarker. Cortical atrophy was quantified by measuring the volume and surface area of the cortex across the whole brain using an automated pipeline in MIMICS. A stepwise multivariate regression analysis was conducted to investigate the correlation between the participants' measured cortical volume and surface area with other potential factors that may influence their susceptibility to developing Alzheimer's disease. The results of the study showed both part volume and surface area generic model fit to be statistically significant at (p = 0.0004) and (p = 0.011) respectively. While the age weighting showed overall significant difference in both part surface area and volume measured by MIMICS at (P = 0.019) and (P = 0.0075), the age group 65 -70 years appear most significant at (P< 0.001). In addition, the performance metrics conducted to evaluate the capability of the model showed an accuracy of 0.68. The study demonstrates the promising utility of voxel-based morphometry using MIMICS, though developing the autom (open full item for complete abstract)

Committee: Tarun Goswami D.Sc. (Advisor); Jaime Ramirez-Vick Ph.D. (Committee Member); Vic Middleton Ph.D. (Committee Member) Subjects: Biomedical Engineering

PhD, University of Cincinnati, 2009, Medicine : Neuroscience/Medical Science Scholars Interdisiplinary

INTRODUCTION: Lead is a potent environmental toxicant. Childhood lead exposure is associated with persistent cognitive and behavioral deficiencies, suggesting underlying neuroanatomic changes. This dissertation is an investigation of the effects of childhood lead exposure on young adult gray matter volume and white matter structure. METHODS: We investigated a subset of the long-running Cincinnati Lead Study, a prospective birth cohort study investigating the effects of environmental lead exposure on a primarily black, urban inner-city cohort. Participants received 23 serial assessments of blood lead concentration during childhood, high-resolution volumetric magnetic resonance imaging at approximately 21 years of age, and diffusion tensor imaging at approximately 24 years of age. Associations between gray matter volume and mean childhood blood lead, and yearly mean blood lead levels from years 1 to 6, were investigated by adjusted voxel-wise multiple regression analysis using voxel-based morphometry (VBM) techniques. Associations between mean childhood lead levels and white matter diffusivity changes were investigated using adjusted multiple regression analyses. RESULTS: Mean childhood lead levels were associated with significant adult gray matter volume loss, particularly in the frontal lobes, and particularly in men. Analysis of yearly mean blood lead levels revealed that blood levels later in childhood were more strongly associated with adult gray matter volume loss than earlier blood lead levels. The most extensive and significant regions of lead-associated gray matter volume loss were found in the frontal lobes of men associated with lead levels measured later at 5 and 6 years of age. Investigation of white matter diffusivity changes by diffusion tensor imaging analysis revealed widespread changes in fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity. The observed patterns of diffusivity changes was consistent with signific (open full item for complete abstract)

Committee: Kim Cecil PhD (Advisor); Caleb Adler MD (Committee Member); James Herman PhD (Committee Member); Bruce Lanphear MD MPH (Committee Member); M. Douglas Ris PhD (Committee Member); Stephen Woods PhD (Committee Member) Subjects: Health; Neurology; Radiology