Evaluation of the sup 11 CO sub 2 positron emission tomographic method for measuring brain pH. II. Quantitative pH mapping in patients with ischemic cerebrovascular diseases

Journal Article · Fri Dec 01 00:00:00 EST 1989 · Journal of Cerebral Blood Flow and Metabolism; (USA)

DOI:https://doi.org/10.1038/jcbfm.1989.120· OSTI ID:5029251

Senda, M; Alpert, N M; Mackay, B C; Buxton, R B; Correia, J A; Weise, S B; Ackerman, R H; Dorer, D; Buonanno, F S ^[1]

---

1. Massachusetts General Hospital, Boston (USA)

A practical method has been developed that, using {sup 11}CO{sub 2} and positron emission tomography (PET), computes and maps (a) effective pH (pHt), a weighted average of intra- and extracellular pH, and (b) clearance (K1), product of blood flow and {sup 11}CO{sub 2} extraction. This method, together with measurements of cerebral blood flow (CBF) and oxygen extraction fraction (OEF), was applied to 12 patients with cerebral ischemia or stroke. The regional K1 was positively correlated with CBF (n = +0.78). The k1/CBF ratio, representing the extraction fraction ratio of {sup 11}CO{sub 2} to H2 15O, was negatively correlated with CBF (r = -0.54), suggesting that {sup 11}CO{sub 2} extraction decreases as flow increases. In five acute stroke patients within 2 days of onset, the injured cortex had lower CBF (20.6 ml/min/100 g), higher OEF (78.1%), and lower pHt (6.96) than the contralateral cortex (CBF = 41.4 ml/min/100 g, OEF = 53.3%, pHt = 7.00), suggesting intracellular acidosis with intact cell membranes. In three stroke patients 5-8 days after onset, the injured cortex had higher CBF (60.9 ml/min/100 g), lower OEF (32.0%), and higher pHt (7.12) than the contralateral cortex (CBF = 45.3 ml/min/100 g, OEF = 58.0%, pHt = 7.06), which suggested an increase in extracellular volume compartment reflecting loss of cell membrane integrity. This method provides information on the regional tissue acid-base status and cell membrane integrity, which may be prognostic of tissue viability.

• OSTI ID: 5029251
• Journal Information: Journal of Cerebral Blood Flow and Metabolism; (USA), Vol. 9:6; ISSN 0271-678X
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BRAIN
POSITRON COMPUTED TOMOGRAPHY
CEREBRAL CORTEX
BLOOD FLOW
ISCHEMIA
DIAGNOSIS
CARBON 11
CARBON DIOXIDE
CELL MEMBRANES
MAN
MATHEMATICAL MODELS
OXYGEN 15
PATIENTS
PH VALUE
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CARBON COMPOUNDS
CARBON ISOTOPES
CARBON OXIDES
CARDIOVASCULAR DISEASES
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
CEREBRUM
CHALCOGENIDES
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
DISEASES
EMISSION COMPUTED TOMOGRAPHY
EVEN-ODD NUCLEI
ISOTOPES
LIGHT NUCLEI
MAMMALS
MEMBRANES
MINUTES LIVING RADIOISOTOPES
NERVOUS SYSTEM
NUCLEI
ORGANS
OXIDES
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PRIMATES
RADIOISOTOPES
TOMOGRAPHY
VASCULAR DISEASES
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics