Imaging Core - South Texas Alzheimer's Disease Research Center

Background

The Imaging Core aims to promote the use of imaging metrics related to brain structure, function, and biochemistry in the study of dementias, including both Alzheimer’s and non-Alzheimer’s types, with a particular focus on Hispanic populations. It plays a pivotal role within the South Texas Alzheimer’s Disease Research Center by providing a well-coordinated array of imaging technology, analytical expertise, informatics infrastructure, and training programs. The Imaging Core consists of three main components: the Research Imaging Institute (RII), the Department of Radiology, and the Radiological Sciences Graduate Program (RSGP). The RII serves as a research resource, offering “open laboratory” access to medical imaging equipment and expert guidance. For nearly three decades, it has supported the biomedical research community in San Antonio and throughout Central and South Texas, facilitating both national and international collaborations. The RII is equipped with advanced capital equipment, including four magnetic resonance imaging and spectroscopy (MR/MRSI) systems for humans (two 3-T) and animals (7-T and 12-T), two positron-emission tomography (PET) systems for humans and animals, and two medical cyclotrons for PET-isotope generation (positive and negative ion). Additionally, it has radio-pharmaceutical production facilities that meet FDA-approved (ANDA & IND) and state-licensed cGMP standards. Ancillary capabilities include in-scanner performance control systems for stimulus delivery and response recording, image-guided robotic transcranial magnetic stimulation (irTMS), and computer-based psychometrics and audiometrics. Faculty at the RII offer expertise in image acquisition (including radiochemistry and pulse-sequence editing), image pre-processing, and various levels of statistical analysis, including multivariate network modeling. The Department of Radiology provides exceptional neuroradiologic expertise, featuring three additional clinical 3T MRI systems and PET/CT capabilities. Radiology collaborates with the RII and the Biggs Institute to recruit neuroimaging faculty. The Radiological Sciences Graduate Program supports the center’s educational mission by managing three doctoral programs focused on imaging: Neuroscience Imaging, Human Imaging, and Diagnostic Radiology. The RSGP’s Neuroscience Imaging and Human Imaging programs partner with UT Health San Antonio’s Medical Scientist Training Program to train physician-scientists in the research applications of medical imaging modalities. RSGP coursework and faculty mentors also facilitate the training of postdoctoral fellows and junior faculty, including current and former recipients of F- and K-awards. In Laredo and Harlingen, the core has established partnerships with centers capable of completing the required MRI protocol for the Alzheimer’s Disease Neuroimaging Initiative (ADNI-3).

Aims
Aims:
1. PET Radiochemistry and Image Acquisition: The Imaging Core provides established and novel PET radiopharmaceuticals to quantify hemodynamics, metabolism, receptor density, and disease burden (such as amyloid and tau load). It offers state-of-the-art, quality-controlled PET imaging for both research and clinical care, including scanner validations for multi-site trials.
2. MRI/MRS Image Acquisition: The core offers established and innovative measures of brain structure, function, and biochemistry using MRI, fMRI and MRS. The imaging core services include quality control, RF coil development, pulse-sequence editing, scan protocol development, scanner validations (for participation in multi-site trials), and post-mortem imaging in collaboration with the Neuropathology Core.
3. Image Archiving, Access Control, and Sharing: The core retain all images and a significant amount of ancillary data (such as E-prime files, psychometric and clinical instrument scores, blood chemistries, etc.) in an XNAT archive. Access permissions are project-based and tiered, with access levels determined by the project Principal Investigator (PI). A web interface allows for both local (UT Health San Antonio) and remote access. The XNAT architecture supports multi-site projects and post hoc data sharing (via data-use agreements), which is a focus of our Imaging Core. XNAT pipelines facilitate automated uploads from both acquisition sites (UT Health San Antonio’s Research Imaging Institute and Medical Arts and Research Center) and support customized preprocessing.
4. Image Preprocessing, Statistical Analysis, and Network Modeling: The image analysts supervise image preprocessing (including normalization, artifact removal, and motion correction) and perform standardized statistical analyses (using FSL, SPM, FreeSurfer). Core faculty oversee more advanced statistical analyses and network modeling of imaging data (using ICA, SEM, graph theory, and statistical learning). For analyses that incorporate psychometrics, non-imaging biomarkers, neuropathology and pedigree or genetic data, the Imaging Core collaborates with the Data Management and Statistics Core.
5. Imaging Training and Trial-Design Consulting: The faculty collaborate with the research education component and degree programs to create imaging-research training experiences for graduate students, postdoctoral fellows, and junior faculty. Imaging Core faculty provide trial-design and statistical analysis consulting for all projects involving imaging.