Sickle Cell DiseaseHDDOT CVRNCT07776444
Cerebrovascular Reactivity Measurements With High-Density Diffuse Optical Tomography
A study testing Carbon Dioxide in people with Sickle Cell Disease and Cerebral Stroke, run by Washington University School of Medicine at 1 site in United States.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 6 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Sickle Cell Disease, Cerebral Stroke
- What is being tested?
- Carbon Dioxide
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 120 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Oct 2025to 30 Sep 2032
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 to 70 years
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Washington University in St. Louis
St Louis, Missouri, 63110
Kristin Guilliams, MD, 3144546120, kristinguilliams@wustl.edu
Kristin Guilliams, MD
About this study
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.
Read the 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.
- Conditions
- Sickle Cell Disease, Cerebral Stroke
- Being tested
- Carbon Dioxide
- Keywords
- cerebrovascular reactivity, magnetic resonance imaging, High density diffuse optical tomography
- Medical subject headings
- Anemia, Sickle Cell, Stroke
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Carbon DioxideOther
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.
| Study group | Role | What they receive |
|---|---|---|
| Healthy Controls | Active comparator | Not described Receives: Other: Carbon Dioxide |
| Sickle Cell Anemia Participants | Active comparator | Not described Receives: Other: Carbon Dioxide |
What is being measured
The primary outcome is the main question the study is designed to answer.
HDDOT-Based Cerebrovascular Reactivity
Changes in relative concentration of deoxyhemoglobin with fluctuations of carbon dioxide as compared to gold standard measurement of MRI-based cerebrovascular reactivity.
Measured: ~15 minutes during the MRI scan and ~60 minutes during the HDDOT imaging.
Secondary outcomes (1)
Cerebral Oxygen Metabolism
MRI-based cerebral based blood flow oxygen extraction fraction will be combined with laboratory data estimating arterial oxygen content to calculate cerebral oxygen metabolism.
Measured: From administration of carbon dioxide to end of inhalation of carbon dioxide -- 60 minutes during MRI and/or HDDOT imaging.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Aug 2026
- Study start1 Oct 2025
- Primary completion30 Sep 2030 (estimated)
- Study completion30 Sep 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sickle Cell DiseaseStudies of the same condition, open and under way.
- More trials run by Washington University School of MedicineThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Single group
- Model description
- All arms will receive the same study conditions.
- Masking
- None (open label)
- Enrolment
- 120 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Washington University School of Medicine
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07776444
- Sponsor's protocol ID
- 202508036
- Acronym
- HDDOT CVR
- Status last verified
- Aug 2026
- First submitted
- 22 Sep 2025
- Last updated
- 20 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cerebrovascular Reactivity Measurements With High-Density Diffuse Optical Tomography
- ClinicalTrials.gov ID
- NCT07776444
- Acronym / sponsor ID
- HDDOT CVR / 202508036
- Conditions
- Sickle Cell Disease, Cerebral Stroke
- Keywords
- cerebrovascular reactivity, magnetic resonance imaging, High density diffuse optical tomography
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- Washington University School of MedicineUniversity, hospital or other
- Study start
- 1 Oct 2025 (actual)
- Primary completion
- 30 Sep 2030 (estimated)
- Study completion
- 30 Sep 2032 (estimated)
- First posted
- 20 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- All arms will receive the same study conditions.
| Arm | Type | Receives |
|---|---|---|
| Healthy Controls | Active comparator | Other: Carbon Dioxide |
| Sickle Cell Anemia Participants | Active comparator | Other: Carbon Dioxide |
Who may qualify
- Ages
- 6 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (3 listed)
- 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
Key exclusion criteria (2 listed)
- 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)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Carbon DioxideParticipants 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. | Other | Healthy Controls, Sickle Cell Anemia Participants |
Primary outcome
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.
1 secondary outcome
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.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Aug 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Carbon Dioxide in people with Sickle Cell Disease and Cerebral Stroke, run by Washington University School of Medicine at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 20 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Kristin Guilliams, MD (3144545436, kristinguilliams@wustl.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
HDDOT-Based Cerebrovascular Reactivity (time frame: ~15 minutes during the MRI scan and ~60 minutes during the HDDOT imaging.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Aug 2026; AzTrials last refreshed its copy on 26 Oct 2026.