# High-resolution High-speed Photoacoustic and Ultrasound Imaging of SmallVessel Functions in Ischemic Stroke

> **NIH NIH R01** · DUKE UNIVERSITY · 2022 · $510,039

## Abstract

Abstract:
Ischemic stroke continues to be a leading cause of both mortality and long-term disability worldwide. This is
becoming more pronounced with an increasingly aging population. Many studies, including ours, have revealed
substantial differences between the young and aged brains, including age-associated changes in cerebral
vasculature morphology and blood oxygneation. The first task in treating poststroke brain is to restore the blood
perfusion to the parenchyma, which relies on the integrity of the cerebral vascular network. It has been shown
that small blood vessels (diameters less than 100 µm) experience the most loss after ischemic stroke, resulting
in the impediment of blood reperfusion and a delay in brain remodeling. Moreover, after ischemic stroke, two
major vascular repair processes, arteriogenesis in the acute phase and angiogenesis in the delayed phase, are
activated mostly at the small vessel levels. Both the vascualr impairment and resotration are heterogeneous at
different brain regions affected by ischemia. Therefore, promoting the development of local microvessels has
been recognized as a particularly promising therapeutic strategy. Yet, targeting vascular modeling has not been
successful in clinical stroke mangement, primarily due to our limited understanding of microvascular functions in
poststroke brains, especially in aged brains. Current brain imaging technologies, especially optical microscopy,
variously suffer from low resolution, low speed, and/or shallow penetration depth, and thus cannot fill the needed
knowledge gap. Here, relying on the tehnical innovations such as the fast polygon scanning and ultra-wideband
ultrasound detection, we propose to develop a truly interagred photoacoustic and utlrasound imaging system
(iPAUSI) that will provide clear advantages over other imaging modalities. iPAUSI will offering longitudinal
structural and functional measurements of small vessels, including vascular morphology (density, volume,
tortuosity), blood flow, and blood oxygenation, with high spatial and temporal details. Enabled by these
capabilities, we will perform a comprehensive analysis of small vascular impairment and remodeling in the
poststroke mouse brain. Ultimiately, we expect to obtain detailed information of collateral remodeling of small
vessels in the acute phase and angiogenesis in the delayed phase, in the aged stroke brains. We will accomplish
our overall objective by pursuing the following specific aims: (1) Aim1: Develop and optimize an integrated
photoacoustic and ultrasound imaging system with high spatial and temporal resolutions. (2) Aim 2: Develop a
set of novel imaging methods to accurately quantify the oxygenation and blood flow of small vessels in deep
brain. (3) Aim 3: Study the age specific effects on small vessel remodeling in ischemic stroke in mice at young
and age. If successful, our results are expected to generate new insights on the aged brains after stroke, which
will inform developmen...

## Key facts

- **NIH application ID:** 10471807
- **Project number:** 5R01NS111039-04
- **Recipient organization:** DUKE UNIVERSITY
- **Principal Investigator:** Junjie Yao
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $510,039
- **Award type:** 5
- **Project period:** 2019-09-15 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10471807

## Citation

> US National Institutes of Health, RePORTER application 10471807, High-resolution High-speed Photoacoustic and Ultrasound Imaging of SmallVessel Functions in Ischemic Stroke (5R01NS111039-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10471807. Licensed CC0.

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