Integrated PET/MR Assessment of Brain Recovery After Recanalization of Non-Acute Atherosclerotic MCA Occlusion

November 4, 2026 updated by: Han Ju, Qianfoshan Hospital

RESTORE: A Prospective Observational Study of Perfusion-Metabolism Recoupling and Functional Network Recovery After Recanalization of Non-Acute Atherosclerotic Middle Cerebral Artery Occlusion Using Integrated PET/MR

Restoration of arterial patency following recanalization of non-acute atherosclerotic middle cerebral artery (MCA) occlusion may improve cerebral blood supply. However, the extent to which restored perfusion is accompanied by changes in cerebral metabolism and functional brain network organization remains incompletely understood.

This prospective observational study, RESTORE, aims to characterize cerebral perfusion-metabolism recoupling and functional network recovery in patients with non-acute atherosclerotic MCA occlusion who undergo clinically indicated recanalization.

Integrated positron emission tomography/magnetic resonance imaging (PET/MR) will be used to assess cerebral perfusion, metabolic activity, and brain functional connectivity at protocol-defined time points. Imaging measurements will be evaluated in relation to vascular characteristics, recanalization status, and neurological and cognitive outcomes, as applicable.

The study seeks to clarify the temporal and spatial relationships among reperfusion, metabolic changes, and functional network reorganization, and to explore imaging markers associated with clinical recovery after recanalization.

The decision to perform recanalization and the selection of treatment strategies will be based on routine clinical care and will not be assigned by the observational study protocol.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Background and Rationale: Non-acute atherosclerotic MCA occlusion can result in persistent cerebral hypoperfusion, altered metabolic activity, and disruption of functional brain networks. Although recanalization can restore arterial patency in selected patients, anatomical reopening of an occluded artery does not necessarily indicate complete restoration of tissue-level perfusion, cerebral metabolism, or neuronal network function.

Cerebral perfusion and metabolism are closely related under physiological conditions. Chronic hypoperfusion may disrupt this relationship, while successful revascularization may facilitate subsequent physiological adaptation. The timing, magnitude, and distribution of perfusion-metabolism recoupling after recanalization remain uncertain.

Integrated PET/MR allows complementary evaluation of cerebral hemodynamics, tissue metabolic activity, structural abnormalities, and functional connectivity. Its multimodal capabilities may provide a more comprehensive assessment of cerebral recovery than vascular imaging alone.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
15

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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Shandong
      • Jinan, Shandong, China, 261053
        • Recruiting
        • The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital
        • Contact:
        • Principal Investigator:
          • Ju Han, MD

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

N/A

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of patients with non-acute atherosclerotic MCA occlusion who are evaluated for recanalization at participating clinical centers.

Eligible patients undergoing clinically indicated recanalization will be invited to participate in prospective PET/MR imaging assessments and clinical follow-up.

Description

Inclusion Criteria:

  1. Aged 18-80 years, regardless of sex.
  2. Symptomatic non-acute middle cerebral artery (MCA) occlusion, with an interval of ≥4 weeks between the most recent ischemic event or imaging confirmation of occlusion and the recanalization procedure.
  3. Occlusion involving the M1 segment of the MCA, confirmed by computed tomography angiography (CTA), magnetic resonance angiography (MRA), or digital subtraction angiography (DSA).
  4. Occlusion presumed to be of atherosclerotic origin.
  5. Persistence of at least one of the following despite guideline-directed medical therapy: recurrent transient ischemic attacks (TIAs), minor ischemic stroke, symptoms attributable to cerebral hypoperfusion, watershed infarction, or imaging evidence of cerebral hypoperfusion or metabolic abnormalities.
  6. Preoperative PET/MR images of sufficient quality for quantitative analysis.
  7. Clinically scheduled to undergo endovascular recanalization.
  8. Provision of written informed consent by the patient or their legally authorized representative.

Exclusion Criteria:

  1. Acute large-territory cerebral infarction involving more than one-third of the MCA territory.
  2. Extensive encephalomalacia within the affected vascular territory that precludes reliable assessment of cortical regions of interest (ROIs).
  3. Non-atherosclerotic causes of MCA occlusion, including moyamoya disease, arterial dissection, central nervous system vasculitis, or cardioembolism.
  4. Severe bilateral intracranial arterial occlusive disease that precludes reliable calculation of hemispheric asymmetry indices.
  5. Structural lesions involving the cerebellum or brainstem that may interfere with metabolic analysis using the cerebellum as a reference region.
  6. Contraindications to MRI (e.g., incompatible cardiac pacemakers, metallic foreign bodies, or severe claustrophobia) or PET imaging.
  7. Severe head motion or imaging artifacts that render PET/MR, arterial spin labeling (ASL), or blood oxygen level-dependent (BOLD) imaging data unsuitable for analysis.
  8. Poor glycemic control (fasting blood glucose >11.1 mmol/L) that may compromise the quality of 18F-fluorodeoxyglucose (18F-FDG) PET 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

  • Observational Models: COHORT
  • Time Perspectives: PROSPECTIVE

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Perfusion-Metabolism Abnormality Burden in the Affected Hemisphere From Baseline to 1 Month After Recanalization (ΔPMB)
Time Frame: Baseline and 1 Month After Recanalization;

The cerebral perfusion-metabolism coupling index will be derived from spatially corresponding cerebral perfusion and PET-based metabolic measurements within prespecified regions of interest in the affected MCA territory. The exact coupling metric, its calculation, normalization, and interpretation will be defined in the prespecified imaging analysis protocol. The primary measure will be the within-participant change in this index between baseline and the specified follow-up visit.
Baseline and 1 Month After Recanalization;

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Regional Cerebral Blood Flow From Baseline to 1 Month After Recanalization;
Time Frame: Preoperative baseline and 1 month after recanalization.

Cerebral blood flow (CBF) in the affected hemisphere will be quantified using arterial spin labeling (ASL) MRI, expressed in mL/100 g/min. The change in CBF will be calculated as the value at 1 month after recanalization minus the preoperative baseline value.
Preoperative baseline and 1 month after recanalization.
Change in Arterial Cerebral Blood Volume in the Affected Hemisphere
Time Frame: Baseline and 1 Month After Recanalization;

Arterial cerebral blood volume (aCBV) in the affected hemisphere will be quantified using the prespecified ASL-derived imaging method. The change in aCBV will be calculated as the value at 1 month after recanalization minus the preoperative baseline value.
Baseline and 1 Month After Recanalization;
Change in Arterial Transit Time in the Affected Hemisphere
Time Frame: Baseline and 1 Month After Recanalization;

Arterial transit time (ATT) will be quantified using the prespecified ASL MRI technique and expressed in milliseconds. The change in ATT will be calculated as the value at 1 month after recanalization minus the preoperative baseline value.
Baseline and 1 Month After Recanalization;
Change in 18F-FDG Standardized Uptake Value Ratio in the Affected Hemisphere
Time Frame: Baseline and 1 Month After Recanalization;

Cerebral glucose metabolism will be assessed using 18F-fluorodeoxyglucose (18F-FDG) PET. The standardized uptake value ratio (SUVR) will be calculated using the prespecified reference region and expressed as a dimensionless ratio. The change in SUVR will be calculated as the value at 1 month after recanalization minus the preoperative baseline value.
Baseline and 1 Month After Recanalization;
Change in Hemispheric Asymmetry Index of Cerebral Blood Flow
Time Frame: Baseline and 1 Month After Recanalization;

The hemispheric asymmetry index of cerebral blood flow (CBF-AI) will be calculated from corresponding CBF measurements in the affected and contralateral hemispheres using the prespecified asymmetry formula. The change will be calculated as the index at 1 month after recanalization minus the baseline index.
Baseline and 1 Month After Recanalization;
Change in Hemispheric Asymmetry Index of Arterial Cerebral Blood Volume
Time Frame: Baseline and 1 Month After Recanalization;

The hemispheric asymmetry index of arterial cerebral blood volume (aCBV-AI) will be derived from aCBV measurements in the affected and contralateral hemispheres using the prespecified asymmetry formula. The change will be calculated as the index at 1 month after recanalization minus the baseline index.
Baseline and 1 Month After Recanalization;
Change in Hemispheric Asymmetry Index of Arterial Transit Time
Time Frame: Baseline and 1 Month After Recanalization;

The hemispheric asymmetry index of arterial transit time (ATT-AI) will be calculated from ATT measurements in the affected and contralateral hemispheres using the prespecified asymmetry formula. The change will be calculated as the index at 1 month after recanalization minus the baseline index.
Baseline and 1 Month After Recanalization;
Change in Hemispheric Asymmetry Index of 18F-FDG Standardized Uptake Value Ratio
Time Frame: Baseline and 1 Month After Recanalization;

Change in Hemispheric Asymmetry Index of 18F-FDG Standardized Uptake Value Ratio
Baseline and 1 Month After Recanalization;
Proportion of Brain Regions Showing Spatially Concordant Perfusion and Metabolic Improvement After Recanalization
Time Frame: Baseline and 1 Month After Recanalization;

Integrated PET/MR will be used to identify regions of interest (ROIs) exhibiting both perfusion improvement and metabolic improvement at 1 month after recanalization compared with preoperative baseline. Spatial coupling will be quantified as the percentage of evaluable ROIs demonstrating concordant improvement in both parameters, according to prespecified quantitative thresholds and spatial matching criteria.
Baseline and 1 Month After Recanalization;
Change in Global Efficiency of Resting-State Functional Brain Networks
Time Frame: Baseline and 1 Month After Recanalization;

Resting-state functional MRI will be used to construct whole-brain functional connectivity networks. Global efficiency will be calculated using graph-theoretical analysis as a quantitative measure of network-wide information integration. The change in global efficiency will be calculated as the value at 1 month after recanalization minus the preoperative baseline value.
Baseline and 1 Month After Recanalization;
Change in Interhemispheric Functional Connectivity Strength
Time Frame: Baseline and 1 Month After Recanalization;

Interhemispheric functional connectivity will be assessed using resting-state blood oxygen level-dependent (BOLD) MRI. Connectivity strength between prespecified corresponding regions in the two hemispheres will be quantified using Fisher z-transformed correlation coefficients. The change will be calculated as the value at 1 month after recanalization minus the preoperative baseline value.
Baseline and 1 Month After Recanalization;
Change in Nodal Efficiency of Prespecified Brain Network Hubs
Time Frame: Preoperative baseline and 1 month after recanalization.

Nodal efficiency of prespecified key brain regions will be calculated from resting-state functional connectivity networks using graph-theoretical analysis. Changes in nodal efficiency will be evaluated by comparing measurements obtained before recanalization and at 1 month after recanalization. The regions of interest and the summary metric will be defined in the prespecified imaging analysis protocol.
Preoperative baseline and 1 month after recanalization.
Correlation Between 1-Month Change in Perfusion-Metabolism Abnormality Burden and Modified Rankin Scale Score at 90 Days
Time Frame: Preoperative baseline and 1 month after recanalization.

The association between the change in perfusion-metabolism abnormality burden (ΔPMB) from baseline to 1 month after recanalization and functional disability at 90 days will be assessed. Functional disability will be measured using the modified Rankin Scale (mRS), ranging from 0 (no symptoms) to 6 (death), with higher scores indicating greater disability. The association will be quantified using a prespecified correlation coefficient.
Preoperative baseline and 1 month after recanalization.
Correlation Between 1-Month Change in Perfusion-Metabolism Abnormality Burden and Barthel Index Score at 90 Days
Time Frame: Preoperative baseline, 1 month after recanalization (ΔPMB), and 90 days after recanalization (Barthel Index).

The association between ΔPMB from baseline to 1 month after recanalization and activities of daily living at 90 days will be assessed. Functional independence will be measured using the Barthel Index (BI), ranging from 0 to 100, with higher scores indicating greater independence in activities of daily living. The association will be quantified using a prespecified correlation coefficient.
Preoperative baseline, 1 month after recanalization (ΔPMB), and 90 days after recanalization (Barthel Index).
Correlation Between 1-Month Change in Perfusion-Metabolism Abnormality Burden and EQ-5D Health Utility Index at 90 Days
Time Frame: Preoperative baseline, 1 month after recanalization (ΔPMB), and 90 days after recanalization (EQ-5D).

The association between ΔPMB from baseline to 1 month after recanalization and health-related quality of life at 90 days will be assessed using the EuroQol 5-Dimension (EQ-5D) questionnaire. EQ-5D responses will be converted into a health utility index using the prespecified instrument version and population-specific value set. Higher utility scores generally indicate better health-related quality of life. The association will be quantified using a prespecified correlation coefficient.
Preoperative baseline, 1 month after recanalization (ΔPMB), and 90 days after recanalization (EQ-5D).

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Qianfoshan Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Ju Han, MD, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 21, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 4, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 4, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 10, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 10, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 4, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • RESTORE

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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.

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