# Quantitative characterization of human subcortical hemodynamic response

> **NIH NIH K25** · BAYLOR COLLEGE OF MEDICINE · 2020 · $144,317

## Abstract

Project summary
Subcortical human brain regions play critical roles in functions from homeostasis to cognition. However, there
has been a dearth of research on full assessments of human subcortical health. Quantitative characterization
of subcortical responses has a great potential to unveil the mechanisms of various neurodegenerative
disorders including Alzheimer's, Huntington's, and Parkinson's Disease and cerebrovascular pathology such
as traumatic brain injury (TBI).
 Here, we use functional magnetic resonance imaging (fMRI) to measure the blood oxygen level dependent
(BOLD) response in subcortical regions. We will create simple multisensory integration tasks that produce
BOLD response evoked by this brief brain activation – so called BOLD hemodynamic response function (HRF).
We will also use various MRI methods such as proton-density weighted imaging (PDWI), and diffusion tensor
imaging (DTI) for structural assessments. BOLD HRF combined with PDWI and DTI will enable remarkably
complete assessments of subcortical neurovascular health, including quantification of nuclear volumes, white
matter connectivity, and correlations among these metrics. In the proposed research study, we will obtain
health control database for this novel metrics.
 We will develop a novel biomechanical transport model to predict underlying cerebral blood flow and
oxygen metabolism corresponding to BOLD HRFs. We will also develop a simple but effective linear flow
model based on an electrical circuit analogy to show mechanisms of blood flow response driven by local neural
activity. This flow network model will be validated with flow measurement from arterial spin labelling perfusion
MR imaging. The proposed model will address a critical gap in our knowledge of subcortical cerebrovascular
physiology.
 We will test our measurement and modeling schemes for characterization of subcortical HRFs in the mild
traumatic brain injury (TBI) population. This will demonstrate the feasibility of our metrics as clinical diagnostic
tools. The proposed experimental and modeling schemes can be applied more broadly to other brain regions,
such as cerebral cortex. It will be a very effective and reliable diagnostic tools, especially for neurological
disorders and cerebrovascular pathology that cause functional deficits without structural abnormality, such as
subarachnoid hemorrhage, early stage Alzheimer's disease, and mild cognitive impairment.

## Key facts

- **NIH application ID:** 9843719
- **Project number:** 5K25HL131997-04
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **Principal Investigator:** JungHwan Kim
- **Activity code:** K25 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $144,317
- **Award type:** 5
- **Project period:** 2017-01-01 → 2022-01-09

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9843719

## Citation

> US National Institutes of Health, RePORTER application 9843719, Quantitative characterization of human subcortical hemodynamic response (5K25HL131997-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9843719. Licensed CC0.

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