Cerebrovascular Reactivity Measurements With High-Density Diffuse Optical Tomography (HDDOT CVR)

August 17, 2026 updated by: Washington University School of Medicine

The purpose of the study protocol is to identify imaging biomarkers for brain tissue under high metabolic stress at risk for permanent injury. We will measure oxygen extraction fraction (OEF) and cerebrovascular reactivity (CVR) in participants with and without perturbations in cerebral oxygen delivery over time to determine each parameter's role in clinical and radiologic neurologic outcomes. Measuring OEF can be done with specialized MRI sequences. Measuring CVR requires a vasoactive response, such as carbon dioxide. In order to deliver carbon dioxide evenly and as safely as possible, we will use RespirACT, an MRI-compatible device, to prevent over-breathing carbon dioxide and allow rapid steady-state physiology to minimize total scan time. We will also use a high density diffuse optical tomography (HD-DOT) cap to assess the measurement of OEF and CVR. This study will investigate both regional OEF and CVR simultaneously to understand each marker's unique developmental trajectory and contribution to stroke risk in children. This work will expand insights into mechanisms of stroke in children and assess the feasibility of the HD-DOT cap for obtaining these insights by comparing a cohort of optical CVR and a cohort of MRI CVR.

In addition to the MRI and/or HD-DOT cap with RespirAct, participants may also have their vitals measured, complete cognitive testing, and complete a blood draw with a study visit. Participants may be followed for up to three years and may complete both an MRI scan and an HD-DOT scan within 1 week-12 months of each other. Participants may be invited back to repeat MRI and/or HD-DOT scans 1-2 times over the next three years.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The purpose of the study protocol is to identify imaging biomarkers for brain tissue under high metabolic stress at risk for permanent injury. We will measure OEF and CVR in participants with and without perturbations in cerebral oxygen delivery over time to determine each parameter's role in clinical and radiologic neurologic outcomes. Measuring OEF can be done with specialized MRI sequences. Measuring CVR requires a vasoactive response, such as carbon dioxide. In order to deliver carbon dioxide evenly and as safely as possible, we will use RespirACT, an MRI-compatible device, to prevent over-breathing carbon dioxide and allow rapid steady-state physiology to minimize total scan time. We will also use an HD-DOT cap to assess the measurement of OEF and CVR.

Study Type

Interventional

Enrollment (Estimated)

120

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Missouri
      • St Louis, Missouri, United States, 63110
        • Recruiting
        • Washington University in St. Louis
        • Contact:
        • Principal Investigator:
          • Kristin Guilliams, MD
        • Principal Investigator:
          • Adam Eggebrecht

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 6-70 Years Old
  • Able to participate in MRI scan without sedation
  • May or may not have HbSS or beta thalassemia null genotypes of sickle cell anemia

Exclusion Criteria:

  • Significant craniofacial malformation or technical contraindications to DOT monitoring (for HDDOT imaging)
  • Metal in/on the body that is contraindicated for MRI safety (for MRI imaging)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Healthy Controls
Other: Carbon Dioxide
Participants inhale carbon dioxide, delivered by computer-controlled delivery system, to target specific levels of carbon dioxide while in magnetic resonance imaging scan and/or during HDDOT imaging to measure cerebrovascular reactivity.
Active Comparator: Sickle Cell Anemia Participants
Other: Carbon Dioxide
Participants inhale carbon dioxide, delivered by computer-controlled delivery system, to target specific levels of carbon dioxide while in magnetic resonance imaging scan and/or during HDDOT imaging to measure cerebrovascular reactivity.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
HDDOT-Based Cerebrovascular Reactivity
Time Frame: ~15 minutes during the MRI scan and ~60 minutes during the HDDOT imaging.
Changes in relative concentration of deoxyhemoglobin with fluctuations of carbon dioxide as compared to gold standard measurement of MRI-based cerebrovascular reactivity.
~15 minutes during the MRI scan and ~60 minutes during the HDDOT imaging.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cerebral Oxygen Metabolism
Time Frame: From administration of carbon dioxide to end of inhalation of carbon dioxide -- 60 minutes during MRI and/or HDDOT imaging.
MRI-based cerebral based blood flow oxygen extraction fraction will be combined with laboratory data estimating arterial oxygen content to calculate cerebral oxygen metabolism.
From administration of carbon dioxide to end of inhalation of carbon dioxide -- 60 minutes during MRI and/or HDDOT imaging.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Washington University School of Medicine

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 1, 2025

Primary Completion (Estimated)

September 30, 2030

Study Completion (Estimated)

September 30, 2032

Study Registration Dates

First Submitted

September 22, 2025

First Submitted That Met QC Criteria

August 17, 2026

First Posted (Actual)

August 20, 2026

Study Record Updates

Last Update Posted (Actual)

August 20, 2026

Last Update Submitted That Met QC Criteria

August 17, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 202508036

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Subscribe