# Linking in vivo hemodynamics with outcomes in Type B aortic dissection using 4D flow MRI

> **NIH NIH R01** · NORTHWESTERN UNIVERSITY · 2024 · $626,553

## Abstract

PROJECT SUMMARY/ABSTRACT
Type B aortic dissection (TBAD) risk-stratification is increasingly relevant in the era of thoracic
endovascular aortic repair (TEVAR), as outcomes and costs can differ significantly depending on
treatment choice and timing. In addition to clinical and social/demographic risk factors, morphologic
imaging biomarkers such as aorta diameter, entry tear size or locations, and false lumen (FL) thrombus
have been used to predict which patients are at risk of adverse aorta-related outcomes (AARO).
However, these morphologic parameters only indirectly reflect the underlying hemodynamic drivers
(e.g. flow, stasis, and pressure) that lead to AARO.
Our group has shown that 4D flow MRI can in TBAD can measure flow and regurgitation at entry tears
(ET) and quantify true lumen (TL) and FL flow, peak velocity, stasis, and kinetic energy (KE). Our pilot
studies provide strong evidence for the role of these hemodynamic markers for TBAD AARO prediction,
but available data is limited by low patient numbers, heterogenous cohorts, and variable outcome
measures. Additionally, we have identified the following key barriers to clinical translation of 4D flow in
TBAD: 1) image acquisition and analysis is inefficient and not fully validated for accuracy and
reproducibility; 2) it remains unclear which hemodynamic parameters best predict AARO; 3) it is
uncertain if MRA can be used for TEVAR planning (CTA is clinical standard).
The goal of the current proposal is to systematically address these limitations by building on promising
developments already underway in our group to test our central hypothesis: in vivo TBAD
hemodynamics improve predication of patients at high-risk of AARO relative to current
standard-of-care clinical, social/demographic, and morphologic biomarkers. First, we will use
state-of-the-art MRI acceleration and reconstruction techniques to develop and test a dedicated,
clinically translatable rapid, dual-VENC TBAD MRI protocol (Aim 1). We will also perform baseline and
1 year follow-up 4D flow MRI in n=100 acute TBAD patients to determine how hemodynamics compare
to other biomarkers for risk-stratification and AARO prediction (Aim 2). Finally, we will finetune our
existing AI-based 4D flow analysis tools to create an efficient TBAD hemodynamic quantification
pipeline for clinical translation (Am 3). Insights from this study will improve our understanding of the role
of hemodynamics in TBAD pathophysiology and provide new clinical biomarkers for risk assessment.

## Key facts

- **NIH application ID:** 10803674
- **Project number:** 1R01HL168700-01A1
- **Recipient organization:** NORTHWESTERN UNIVERSITY
- **Principal Investigator:** Bradley David Allen
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $626,553
- **Award type:** 1
- **Project period:** 2024-02-15 → 2029-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10803674

## Citation

> US National Institutes of Health, RePORTER application 10803674, Linking in vivo hemodynamics with outcomes in Type B aortic dissection using 4D flow MRI (1R01HL168700-01A1). Retrieved via AI Analytics 2026-06-01 from https://api.ai-analytics.org/grant/nih/10803674. Licensed CC0.

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