NCT07776444 · Washington University School of Medicine
Cerebrovascular Reactivity Measurements With High-Density Diffuse Optical Tomography
(HDDOT CVR)
What this study is about
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.
View original scientific 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 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.
Interventions
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.
Primary outcome measures
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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)
Where
- St Louis, Missouri
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Aug 20, 2026 · Source of record for eligibility and locations