Dynamic Magnetic Resonance Imaging of Human Subarachnoid Space Using Intrathecal Gadolinium Contrast

September 11, 2026 updated by: National Institute of Neurological Disorders and Stroke (NINDS)

Background:

Cerebrospinal fluid (CSF) is the liquid that fills the space around the brain and spinal cord. Researchers do not fully understand how CSF flows and drains around the brain. They want to test a tracer (gadobutrol)-a special dye injected into the CSF-to find out if it is safe to use and can help them get clearer pictures of the CSF during magnetic resonance imaging (MRI) scans of the brain.

Objective:

To test gadobutrol in the CSF during MRI scans of healthy people.

Eligibility:

Healthy volunteers aged 18 years and older. They must be screened under NIH protocol 89N0045.

Design:

Participants will check into the clinic for a 3-day stay.

They will have a lumbar puncture: An area on their lower back will be numbed. A thin needle will be inserted into the space around the spinal cord. A sample of CSF will be taken for research. Then a low dose of gadobutrol will be injected into the CSF.

Participants will have 4 or 5 MRI scans of the brain-30 minutes, 4 hours, 8 hours (this one is optional), 24 hours, and 48 hours after receiving the gadobutrol.

For the scan, they will lie on a table that slides into a cylinder. Special padding will be used to hold their head still. The MRI uses magnetic fields to create images of the inside of the body. Blood and urine samples will also be collected at each scan.

Participants will return for an additional MRI 1 week after they leave the clinic. They will have 2 follow-up phone calls 4 and 12 weeks after the start of the study.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Study Description:

In this study, we will gather safety data on and establish the technical feasibility of bypassing the blood-brain-barrier (BBB) with intrathecal (IT) gadolinium-based contrast agent (GBCA) tracer injection (0.25 ml gadobutrol at a concentration of 1.0 mmol/ml) to dynamically image the subarachnoid space (SAS) in human healthy volunteers. We will also obtain preliminary data on whether this approach will enable us to reliably visualize physiological meningeal lymphatic drainage pathways within the parasagittal dura (PSD) and connections to cerebrospinal fluid (CSF) compartments using serial contrast-enhanced magnetic resonance imaging (CE-MRI) with minimal confounding signal from tracer blood egress. In exploratory analysis, we will quantify temporal clearance kinetics and investigate distribution patterns of GBCA enhancement in the PSD, CSF spaces, and brain parenchyma in up to 12 healthy volunteers using repeated in vivo CE-MRI over 10 days. Safety/tolerability of the IT GBCA administration will be assessed descriptively over the entire 12-week study period.

Objectives:

Primary objective: To track safety/tolerability of IT GBCA administration in healthy human volunteers.

Secondary objective: To establish technical feasibility of dynamic subarachnoid-space imaging using IT GBCA administration in healthy human volunteers.

Exploratory objectives: To explore patterns of dynamic meningeal lymphatic clearance pathway interconnections in vivo under physiological conditions in human healthy volunteers, and to obtain preliminary data regarding the effect of aging on CSF dynamics and CSF-to-blood tracer clearance.

Endpoints:

Primary endpoint: Occurrence of intervention-emergent adverse events at the participant level assessed descriptively over the 12-week study period.

Secondary outcome measure: MRI detection status (yes/no) of contrast in the cerebral SAS at 24 hours.

Exploratory outcome measures: Changes in contrast-to-noise ratio (CNR) and clearance kinetics of SAS to brain parenchyma over 48h.

Study Type

Interventional

Enrollment (Estimated)

15

Phase

  • Phase 1

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 Contact Backup

Study Locations

  • United States
    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institutes of Health Clinical Center
        • Contact:
        • Contact:

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

  • INCLUSION CRITERIA:

To be eligible to participate in this study, an individual must meet all the following criteria:

  • Healthy volunteer.
  • Age >= 18 years.

To explore age-related effects on tracer dynamics and clearance, 3 cohorts of participants will be recruited: 1) 18-30 years, 2) 30-55 years, and 3) >55 years; with 2 males and 2 females in each age group.

  • Able to give written and oral informed consent.
  • Prior evaluation under NIH protocol 89N0045.

EXCLUSION CRITERIA:

An individual who meets any of the following criteria will be excluded from participation in this study:

  • History of chronic neurological illness, or significant concurrent medical illness.
  • Contraindication to 3- or 7-tesla MRI
  • Hypersensitivity reactions to contrast agents.
  • History of severe allergic reactions.
  • Pregnancy or breastfeeding.
  • Renal dysfunction or other serious comorbidities.
  • Platelet count <100,000/microliter, INR > 1.5 or prolonged PT or aPTT at baseline.
  • Any of the following imaging findings: Mass effect, midline shift, herniation (tonsillar, uncal, subfalcine), or Chiari malformation.
  • History of seizures or seizure disorder.
  • Anti-coagulation therapy.
  • Unwilling to allow coded samples to be processed offsite.
  • Unwilling to have coded samples and/or data saved or used in other studies.

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: Other
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Healthy Volunteer
0.25 mmol IT gadobutrol or 0.5 mmol
Drug: Gadobutrol
contrast agent

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Occurrence of intervention-emergent adverse events at the participant level assessed descriptively
Time Frame: 12-week study period.
Systematic recording of adverse events is essential to determine the safety of IT gadobutrol, especially given its off-label use in healthy volunteers. With the limited sample size of this Phase 1 study, safety assessment is appropriately based on a descriptive evaluation rather than formal hypothesis testing. Monitoring known procedure- and contrast-related risks (e.g., post-lumbar puncture headache, nausea, dizziness) as well as any unexpected adverse events over the study and follow-up period provides the critical foundation for ethical justification and regulatory decision-making and is a prerequisite for future feasibility and efficacy-driven studies.
12-week study period.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Participant-level MRI detection status (yes/no) of contrast in the cerebral SAS
Time Frame: 24 hours
Technical feasibility is assessed by determining whether IT administered GBCA can be visually detected in the cerebral SAS at 24 hours under exploratory Phase 1 conditions. As this is a pilot safety study with limited prior human data, feasibility is not used as a stopping criterion. Instead, MRI visibility of contrast will inform adaptive dose escalation. If no or insufficient contrast enhancement is observed in 3 to 5 participants at the initial dose level (0.25 ml), the dose may be escalated to 0.5 ml to improve detectability. This predefined adaptation is intended to support appropriate dose selection for subsequent studies while maintaining the focus on safety.
24 hours

Collaborators and Investigators

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

Sponsor

National Institute of Neurological Disorders and Stroke (NINDS)

Investigators

  • Principal Investigator: Daniel S Reich, M.D., National Institute of Neurological Disorders and Stroke (NINDS)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

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 (Estimated)

September 17, 2026

Primary Completion (Estimated)

March 15, 2028

Study Completion (Estimated)

March 15, 2028

Study Registration Dates

First Submitted

August 29, 2026

First Submitted That Met QC Criteria

August 29, 2026

First Posted (Actual)

September 1, 2026

Study Record Updates

Last Update Posted (Actual)

September 14, 2026

Last Update Submitted That Met QC Criteria

September 11, 2026

Last Verified

August 25, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 10002744
  • 002744-N

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All IPD that results in publication

IPD Sharing Time Frame

6 months after publication

IPD Sharing Access Criteria

IPD will be shared under tech transfer agreements.

IPD Sharing Supporting Information Type

  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

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.

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