Assessment of Structural Brain Changes Related to Anoxic Coma Using High-field and Very Low Field Mobile MRI

NCT07177755 | Not Yet Recruiting

• 2 other identifiers: RC31/22/03132025-A00643-46
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

Standard predictors of outcome after cardiac arrest (CA) have substantial limitations in terms of reliability and generalizability. By providing brain structural connectivity maps, or connectomes, advanced MRI techniques, operating through high-strength magnetic field (HF; 1.5 to 3-T), have precisely revealed white and grey brain matter damages induced by CA, and have demonstrated the high sensitivity and specificity of these indicators for predicting neurological outcome after CA. However, HF MRI requires rigid safety precautions, highly trained technicians and patient transport to dedicated hospital imaging suites, hindering the implementation of these promising neuroimaging techniques in the setting of critical illness. Interestingly, a recent report demonstrates the capability of a proof-of-concept very low-field (VLF; 0.064-T) mobile MRI to obtain neuroimaging at the bedside in critically ill patients. Nevertheless, the spatial resolution of VLF-MRI seems low and there is no available evidence about the use of VLF-MRI to extract highly needed new predictors of neurological recovery based on critical brain structural connectomes. The CUBE project holds the promise of providing a radical paradigm shift in the field of neuroprognostication of anoxic coma patients. The current proposal is a "proof-of concept" study which aims to compare for the first time, HF, VLF and enhanced VLF (recon-VLF) structural connectomes from anoxic coma patients and healthy subjects across the time (3 paired HF and VLF brain scan across the first two weeks after CA). To obtain recon-VLF data, the Investigators will use an ensemble of ground-breaking methods to increase the native spatial resolution of VLF-MRI data. The whole brain imaging dataset will be used to prepare future neuroprognostication studies based on fully bedside assessment of brain structural integrity after CA.

Conditions

Anoxic Coma; Cardiac Arrest (CA); Anoxia-Ischemia, Brain; Coma

Keywords

Anoxic Coma; Cardiac arrest; VLF MRI; HF MRI; structural brain; connectomes

Outcome Measures

Primary Outcomes (1)

• Differences between whole-brain white (WWM-FA) and grey (GMM) matter global metrics independently acquired by HF and VLF-MRI scans very early after coma onset (D0)

  White matter will be assessed by computing the White Matter Fractional Anisotropy (WWM-FA), which ranges from 0 to 1 with lower values related to worse outcomes. Grey matter will be evaluated using Global brain Matter Morphometry (GMM), which encompass both cortical thickness (mm) and deep grey matter volumetry (mm3) assessments, with lower values being associated with poorer outcomes. Both WWM-FA and GMM data will be normalized using brain MRI data obtained from healthy controls (z-scores).

  Day 0

Secondary Outcomes (9)

• Differences between HF and VLF white (WWM-FA=White Matter Fractional Anisotropy ) and grey (GMM=Global brain Matter Morphometry) matter z-scores.

  Day 0

• Differences between HF and VLF white (WWM-FA=White Matter Fractional Anisotropy ) and grey (GMM=Global brain Matter Morphometry) matter z-score

  Day 7

• Differences between HF and VLF white (WWM-FA=White Matter Fractional Anisotropy ) and grey (GMM=Global brain Matter Morphometry) matter z-score

  Day 15

• Paired comparison between recon-VLF, VLF and HF MRI image's quality, using radiometric information metrics (PSNR, SSIM, ERGAS)

  day 0

• Paired comparison between recon-VLF, VLF and HF MRI image's quality, using radiometric information metrics (PSNR, SSIM, ERGAS)

  day 7

Study Arms (2)

Comatose patients after anoxic brain injury

EXPERIMENTAL

Comatose patients after anoxic brain injury Coma, as indicated by a Glasgow Coma Scale (GCS) ≤ 8 (motor score ≤ 2) immediately after CA resuscitation and before sedation onset

Diagnostic Test: High-field and very-low-field MRI acquisitions

Healthy volunteers

OTHER

Healthy volunteers Adult patients matched in age (plus or minus 5 years) and gender to patients

Diagnostic Test: High-field and very-low-field MRI acquisitions

Interventions

High-field and very-low-field MRI acquisitions DIAGNOSTIC_TEST

MRI will be early acquired, as soon as possible after patient hospital admission and always in coma state for patients. For both patients and controls each MRI scanning session will encompass pairs of HF and VLF MRI acquisitions, that will be collected the same day. The main MRI sequences will be: T1, T2, FLAIR and DWI. The VLF spatial resolution recommended by the constructor for all these sequences correspond to voxel size is around 1.5mm/1.5mm/5mm. The total brain scanning time is estimated at 30 minutes.

Comatose patients after anoxic brain injury; Healthy volunteers

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• COMA PATIENTS
• Adult patients (male or female ≥ 18 years).
• Coma, as indicated by a Glasgow Coma Scale (GCS) ≤ 8 (motor score ≤ 2) immediately after CA resuscitation and before sedation onset.
• Written informed consent from patient's legal representative.
• Affiliation to the French social security system
• HEALTHY VOLUNTEERS
• Adult patients (male or female ≥ 18 years).
• Written informed consent.
• Affiliation to the French social security system

You may not qualify if:

• COMA PATIENTS
• Brain death.
• Coma explained by other cause than CA.
• Pregnancy.
• MRI contraindication: medical material not MRI compatible.
• Hemodynamic instability or respiratory failure precluding patient's transport and MRI scanning.
• HEALTHY VOLUNTEERS
• Pregnancy.
• MRI contraindication: medical material not MRI compatible.
• Volunteers who do not wish to be informed of an abnormality detected on MRI a posteriori

Sponsors & Collaborators

• University Hospital, Toulouse: lead
• National Research Agency, France: collaborator
• Institut National de la Santé Et de la Recherche Médicale, France: collaborator

Study Sites (1)

CHU de Toulouse

Toulouse, France

Location

MeSH Terms

Conditions

Heart Arrest; Hypoxia-Ischemia, Brain; Coma

Condition Hierarchy (Ancestors)

Heart Diseases; Cardiovascular Diseases; Brain Ischemia; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Hypoxia, Brain; Vascular Diseases; Hypoxia; Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Unconsciousness; Consciousness Disorders; Neurobehavioral Manifestations; Neurologic Manifestations

Central Study Contacts

Stein SILVA

CONTACT

(+33)5 61 77 97 28; silva.s@chu-toulouse.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Two groups of participants : the first group consists of comatose patients with anoxic brain injury, while the second group consists of healthy participants.

Study Record Dates

• First Submitted: May 20, 2025
• First Posted: September 17, 2025
• Study Start: September 15, 2025
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): March 1, 2029
• Last Updated: September 17, 2025

Record last verified: 2025-09

Locations

FR (1)