This is a decommissioned version of ERA which is running to enable completion of migration processes. All new collections and items and all edits to existing items should go to our new ERA instance at https://ualberta.scholaris.ca - Please contact us at erahelp@ualberta.ca for assistance!
- 66 views
- 101 downloads
Correlation of Subregional Hippocampal Thickness Abnormalities with Positron Emission Tomography Phosphorylated Tau Measurements in Patients with Mild Cognitive Impairment and Alzheimer's Disease
-
- Author / Creator
- Siddique, Muhammad M
-
Alzheimer’s disease (AD) is the most common cause of dementia and is an emerging public health crisis with 150 million cases projected globally by 2050. Biomarkers are playing an emerging role in AD research - however, existing biomarkers have substantial limitations. Magnetic Resonance Imaging (MRI) holds advantages over existing biomarkers as it is non-invasive and does not involve exposure to ionizing radiation. This project aims to utilize MR images to measure subfield thickness throughout the hippocampal long axis using HippUnfold, a recently released open-source automated hippocampal segmentation software, and to correlate these measurements with Positron Emission Tomography (PET) phosphorylated tau (pTau), an extensively validated imaging biomarker for AD. High resolution (0.39x0.39x2mm) Hippocampal MR Images acquired by the Alzheimer's Disease Neuroimaging Initiative (ADNI) were used in the analysis. The right hemisphere cohort included control, n= 281, mild cognitive impairment (MCI, n =219), and AD, (n = 44) and the left hemisphere cohort included control, n= 278, mild cognitive impairment (MCI, n =205), and AD, (n = 41). HippUnfold provided automated segmentation and computed thickness measurements for 5 hippocampal subfields: subiculum and cornu ammonis (CA) 1-4 throughout the entire hippocampal long axis. Previously acquired PET measurements for phosphorylated tau were downloaded from the ADNI database and correlated with thickness measurements along the hippocampal long axis using linear regression models. In our analyses - thickness measurements were strongly correlated with the degree of tau deposition quantified with tau PET. Specifically, we found significant cluster correlation (p < 0.05) throughout the long axis when comparing reduced hippocampal subfield thickness to PET phosphorylated tau Standard Uptake Volume Ratios (SUVRs). Furthermore, we identified regional specificity of maximal thickness abnormalities in our cohort in the body of the subiculum and CA1 in both hemispheres and the head region of CA2-4 in the right hemisphere. Our data add to the previous scientific literature demonstrating subfield-specific hippocampal volume loss throughout the hippocampus in patients with AD.
-
- Subjects / Keywords
-
- Graduation date
- Fall 2023
-
- Type of Item
- Thesis
-
- Degree
- Master of Science
-
- License
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.