Initial cerebral HM-PAO distribution compared to LCBF: use of a model which considers cerebral HM-PAO trapping kinetics

Journal Article · Thu Dec 01 04:00:00 EST 1988 · J. Cereb. Blood Flow Metab.; (United States)

DOI:https://doi.org/10.1038/jcbfm.1988.30· OSTI ID:6786244

Lear, J L

The cerebral uptake of (99mTc)-d,l-hexamethylpropyleneamine oxime complex (HM-PAO) was compared to LCBF determined simultaneously with (14C)iodoantipyrine (IAP) using double radionuclide quantitative digital autoradiography. Awake male rats were given intravenous injections of a mixture of 50 microCi IAP and 15 mCi of HM-PAO and killed 20 s after tracer activity had first reached the brain. Two separate autoradiograms were produced from each 20 microns brain section. The autoradiograms were digitized, corrected for cross-contamination, and then converted into images of individual tracer concentration. The diffusible tracer model was used to convert the IAP concentration images into LCBF images. Regional HM-PAO concentration was found not to be linearly related to LCBF as determined with the IAP, and therefore a simple microsphere type model was inadequate in relating HM-PAO uptake to LCBF. A better HM-PAO uptake--LCBF correlation was obtained when the HM-PAO arterial input function was corrected for very rapidly produced, non-cerebrally extracted, metabolites and a kinetic model was used that considered the rate of intracerebral metabolism of HM-PAO to a retained metabolite. Even using this model, however, some differences between HM-PAO uptake and LCBF occurred in certain brain regions. Because these differences were small and the HM-PAO uptake pattern has been shown to be constant for many minutes, HM-PAO can probably be used to estimate LCBF in patients with single positron emission computed tomography (SPECT) imaging.

• Research Organization: Univ. of Colorado Health Sciences Center, Denver (USA)
• OSTI ID: 6786244
• Journal Information: J. Cereb. Blood Flow Metab.; (United States), Journal Name: J. Cereb. Blood Flow Metab.; (United States) Vol. 8:6; ISSN JCBMD
• Country of Publication: United States
• Language: English

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550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINES
ANIMALS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD FLOW
BODY
BRAIN
CARBON 14 COMPOUNDS
CENTRAL NERVOUS SYSTEM
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
DRUGS
EMISSION COMPUTED TOMOGRAPHY
HOURS LIVING RADIOISOTOPES
HYDROXY COMPOUNDS
INJECTION
INTAKE
INTERMEDIATE MASS NUCLEI
INTRAVENOUS INJECTION
ISOMERIC NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MATHEMATICAL MODELS
METABOLISM
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOMETALLIC COMPOUNDS
ORGANS
OXIMES
RADIOISOTOPES
RADIOPHARMACEUTICALS
RATS
RODENTS
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
TECHNETIUM 99
TECHNETIUM ISOTOPES
TOMOGRAPHY
UPTAKE
VERTEBRATES
YEARS LIVING RADIOISOTOPES