Clinical Trial: Study of Brain Blood Flow During Induced Hypercapnia (Excess Blood Carbon Dioxide)
Study Status: Completed
Recruit Status: Completed
Study Type: Observational
Official Title: MR Perfusion Imaging in Hypercapnia: Development of Technical Protocols
Brief Summary:
This study will evaluate magnetic resonance imaging (MRI ) methods for measuring changes in the brain's blood flow during hypercapnia (a condition of excess carbon dioxide in the blood). MRI is a diagnostic tool that uses a large magnet and radio waves to produce images of the body without X-rays.
Healthy normal volunteers in this study may have as many as six MRI scans over a 2-year period. For this procedure, the person lies on a stretcher placed in a strong magnetic field produced by the MRI machine. During the scan, the person's blood carbon dioxide (CO2 ) levels will be increased either by: 1) breathing air mixtures containing up to 5% CO2; or 2) receiving an intravenous (I.V.) injection of a drug called acetazolamide.
Persons who breathe CO2 will have their heart rate, blood pressure and oxygen levels monitored throughout the procedure. Those receiving acetazolamide will have the drug injected intravenously (I.V.) into an arm vein. If the volunteer experiences any unpleasant side effects from the CO2 or acetazolamide, the study will be stopped.
The information gained from this study will be used to develop better ways to study brain function, possibly leading to better diagnostic and treatment methods.
Detailed Summary: Advances in MR perfusion imaging have provided clinical researchers with the opportunity to quantitate regional increases in cerebral blood flow. The purpose of this study is to acquire the technical experience required to perform MR perfusion imaging studies of the hypercapnic cerebral blood flow response. Cerebral blood flow will be increased by inhalation of carbogen (an air mixture containing 5% CO2) or IV injection of the carbonic anhydrase inhibitor acetazolamide. The technical experience obtained in this study will be used to design a study of the pharmacological and physiological mechanisms underlying cerebral blood flow increases during hypercapnia.
Sponsor: National Institutes of Health Clinical Center (CC)
Current Primary Outcome:
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Original Secondary Outcome:
Information By: National Institutes of Health Clinical Center (CC)
Dates:
Date Received: November 3, 1999
Date Started: September 1999
Date Completion: August 2004
Last Updated: March 3, 2008
Last Verified: August 2004
