11C-Iodoantipyrine for the measurement of regional cerebral blood flow by positron emission tomography. Validation studies

Journal Article · · Stroke; (United States)

DOI:https://doi.org/10.1161/01.STR.12.6.745· OSTI ID:5549980

Ginsberg, M D; Lockwood, A H; Busto, R; Finn, R D; Campbell, J A; Boothe, T E

Positron emission tomography (PET) makes it possible to employ an in vivo autoradiographic paradigm to measure regional cerebral blood flow (rCBF) in man. In this study, we synthesized the positron-emitting radiopharmaceutical 11C-iodoantipyrine (11C-IAP) and validated its suitability as a CBF tracer. 11C ( T and one-half 20.4 min) was produced by the (p,alpha) nuclear reaction on 14N. 11C-methyl iodide was used to methylate 3-methyl-1-phenyl-2-pyrazolin-5-one to form 11C-antipyrine, which was iodinated. Radiochemical purity of the 11C-IAP product was 93-98% except as described below. rCBF was measured with 11C-IAP in nitrous oxide-anesthetized Wistar rats by the method of indicator fractionation, and values were compared with rCBF values measured with simultaneously administered commercially produced 14C-IAP. rCBF was studied over a range of arterial Pco2 values (31-58 mm Hg, mean 43.0 +/- 3.5). Mean rCBF data for the 2 tracers agreed to within 4.8% for cerebral hemispheral samples, 3.8% for cerebellum, and 5.3% for brainstem. Mean values (+/- SEM) for rCBF using 11C-IAP were 1.67 +/- 0.20 ml gm-1 min-1 for cerebral hemispheres; 1.32 +/- 0.17 for cerebellum; and 1.50 +/- 0.21 for brainstem. When chromatographic analysis revealed tracer impurity, rCBF, as measured with 11C-IAP, fell consistently below values obtained with 14C-IAP. The data indicate that 11C-IAP, when properly synthesized and submitted to batch-by-batch quality control, may be suitable for measuring rCBF in man by emission tomography.

• Research Organization: Cerebral Vascular Disease Research Center, University of Miami School of Medicine, Miami Beach, FL
• OSTI ID: 5549980
• Journal Information: Stroke; (United States), Journal Name: Stroke; (United States) Vol. 12:6; ISSN SJCCA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
550901 -- Pathology-- Tracer Techniques
551001 -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ANTIPYRETICS
ANTIPYRINE
AUTORADIOGRAPHY
AZOLES
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BLOOD FLOW
BODY
BRAIN
CARBON 11
CARBON 14 COMPOUNDS
CARBON ISOTOPES
CENTRAL NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM DEPRESSANTS
CEREBRUM
CHEMICAL PREPARATION
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
DIAGNOSTIC USES
DISEASES
DRUGS
EMISSION COMPUTED TOMOGRAPHY
EVEN-ODD NUCLEI
HETEROCYCLIC COMPOUNDS
IN VIVO
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MINUTES LIVING RADIOISOTOPES
NERVOUS SYSTEM
NERVOUS SYSTEM DISEASES
NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PATHOLOGY
PATIENTS
POSITRON COMPUTED TOMOGRAPHY
PYRAZOLES
PYRAZOLINES
RADIOISOTOPES
RADIOPHARMACEUTICALS
SYNTHESIS
TOMOGRAPHY
USES
VASCULAR DISEASES