Hypercapnia and cerebral blood flow: An approach to testing perfusion reserve
Cerebral perfusion patterns of 28 patients with known cerebral vascular pathology and 13 normal volunteers have been studied using fluorine-18 labeled fluoromethane, an inert diffusable radiotracer, and a PET imaging system. All subjects were studied during hypercapnia induced by breathing 5% carbon dioxide as well as while breathing room air. No major changes in subject orientation occurred through acquisition of both data sets. Global perfusion increased consistently during hypercapnia in all subjects but in patients with completed strokes the depressed perfusion values in the infarcted region did not increase. Both recent and older infarcts were found to lack CO/sub 2/ reactivity. The size of the infarct associated perfusion defect was typically larger than that suggested by CT scans particularly early in the post infarct interval. The usefulness of hypercapnia as an approach to assessing perfusion reserve is illustrated by a patient with a totally occluded right internal carotid artery and right hemisphere TIA. Brain perfusion data while he breathed room air were normal while during hypercapnia there was no perfusion increase in the distribution of right anterior and middle cerebral arteries; a 30% increase in perfusion was observed in all other cerebral regions. Computer software which facilitates room air/hypercapnia and region interhemispheric comparisons has been developed enabling faster and more reliable analyses.
- Research Organization:
- Middleton VA Hospital
- OSTI ID:
- 7088137
- Report Number(s):
- CONF-840619-
- Journal Information:
- J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 25:5; ISSN JNMEA
- Country of Publication:
- United States
- Language:
- English
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62 RADIOLOGY AND NUCLEAR MEDICINE
AIR
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BLOOD FLOW
BODY
BRAIN
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CENTRAL NERVOUS SYSTEM
CHALCOGENIDES
COMPUTERIZED TOMOGRAPHY
DATA ACQUISITION
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DIAGNOSTIC USES
DISEASES
EMISSION COMPUTED TOMOGRAPHY
FLUIDS
FLUORINATED ALIPHATIC HYDROCARBONS
FLUORINE 18
FLUORINE ISOTOPES
GASES
HALOGENATED ALIPHATIC HYDROCARBONS
HOURS LIVING RADIOISOTOPES
IMAGE PROCESSING
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
NERVOUS SYSTEM
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PATHOLOGY
PATIENTS
POSITRON COMPUTED TOMOGRAPHY
PROCESSING
RADIOISOTOPES
TOMOGRAPHY
USES
VASCULAR DISEASES