Thursday, October 30th
9:00am - 10:15am, Zoom
Meeting ID: 963 2560 9671
Passcode: 698339
Bibhas Chakraborty, PhD
Associate Professor, Centre for Quantitative Medicine; Interim Director, Centre for Quantitative Medicine
Duke-NUS Medical School
Innovative Trial Designs in Mobile Health Using Reinforcement Learning
Multi-site national and international imaging consortia have formed with the goal of precisely characterizing the human brain across the lifespan. These consortia have succeeded in collecting large samples of brain magnetic resonance imaging (MRI) scans to estimate sex-specific trajectories of brain phenotypes across age, often called brain charts. The promise of brain charts is that future researchers and clinicians will be able to assess a new scan for deviations from this healthy trajectory. However, the implementation of these charts in practice is severely limited by differences across study sites, also known as site effects. Here, we first discuss several projects in harmonization of MRI data specifically tailored to this normative modeling setting. Then, we leverage advancements in model uncertainty quantification to propose new ways to calibrate brain charts, as an alternative to harmonizing data. Finally, we apply our approaches to the Lifespan Brain Chart Consortium (LBCC) to assess generalizability to new scans from both healthy individuals and Alzheimer's disease (AD) patients. Based on our findings, we provide methodological recommendations for applying fitted brain charts to new sites.
Biostatistics Departmental Seminars & Lectures
During the Fall and Spring semesters, the Department of Biostatistics holds regular seminars on Thursdays, called the Levin Lecture Series, on a wide variety of topics which are of interest to both students and faculty. Over each semester, there are also often guest lectures outside the regular Thursday Levin Lecture Series, to provide a robust schedule the covers the wide range of topics in Biostatistics. The speakers are invited guests who spend the day of their seminar discussing their research with Biostatistics faculty and students.