# Evaluation of Aortic Hemodynamics and Compliance in Aortic Stenosis

> **NIH NIH F30** · NORTHWESTERN UNIVERSITY · 2021 · $51,036

## Abstract

Project Summary
Bicuspid aortic valve (BAV) is the most common congenital heart defect, and it predisposes patients to
complications such as aortic stenosis (AS, most common cause) and aortic aneurysm. Current metrics are
ineffective at distinguishing patients with BAV and TAV and concomitant AS, and management of AS in
patients with BAV and trileaflet aortic valves (TAV) is nearly identical under current guidelines. Current clinical
care involves ultrasound as well as CT or contrast enhanced MRI to generate angiograms, and surgical
thresholds are based on diameters and growth rates in the ascending aorta. The goal of this project is to
develop a high-resolution self-navigating bSSFP sequence and then combine it with 4D flow data in an
automated pipeline to allow improved characterization of the anatomy and hemodynamics of the aorta.
While 4D flow, a method pioneered in our lab, enables acquisition of temporally and spatially resolved 3D flow
velocity without using contrast, the technique could be improved by incorporating higher-resolution scans with
improved blood-tissue contrast. Delineation of the volume of the aorta in patients with AS from 4D flow data
alone has also historically proven more challenging due to the presence of a high-speed flow jet. Clinical
translation of 4D flow is also limited by a time-intensive analysis workflow, so this project includes both the
sequence development aims as well as the goal of developing an automated cloud-based analysis pipeline for
the data. Close collaboration with clinicians will ensure that calculated metrics are relevant and presented in a
manner that could be useful in the clinical staging or management of these patients.
The first aim of this proposal is development and validation of a balanced steady-state free-precession
(bSSFP) sequence to collect improved anatomic data with high resolution and blood-tissue contrast to improve
diameter measurements of the ascending aorta and enable segmentation of the aorta at several time points in
the cardiac cycle. This will allow calculation of relative area change as a surrogate for aortic compliance and
examination of the wall shear stress dynamics over the cardiac cycle. The second aim will incorporate this
higher-resolution data and 4D flow data into a highly automated pipeline that will enable rapid segmentation of
the aorta and calculation of the wall shear stress dynamics and relative area changes. In the third aim, 20 BAV
and 20 TAV patients with AS will be recruited from the patient population at Northwestern, then imaged and
analyzed using the new protocol. This will demonstrate the feasibility of using the method in a clinical setting,
while also contributing to answering the question of if AS is a separate clinical entity in BAV and TAV patients.
Clinical collaborators will help guide the project to fulfil the ultimate goal of improving clinical imaging and
staging of these complex patients.

## Key facts

- **NIH application ID:** 10246513
- **Project number:** 5F30HL145995-03
- **Recipient organization:** NORTHWESTERN UNIVERSITY
- **Principal Investigator:** Michael Baran Scott
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $51,036
- **Award type:** 5
- **Project period:** 2019-09-30 → 2023-09-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10246513

## Citation

> US National Institutes of Health, RePORTER application 10246513, Evaluation of Aortic Hemodynamics and Compliance in Aortic Stenosis (5F30HL145995-03). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10246513. Licensed CC0.

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