Delayed L-phenylalanine infusion allows for simultaneous kinetic analysis and improved evaluation of specific-to-nonspecific fluorine-18-dopa uptake in brain.
J Nucl Med
; 33(7): 1383-9, 1992 Jul.
Article
em En
| MEDLINE
| ID: mdl-1613582
ABSTRACT
The accumulation of 3-O-methyl-6-[18F]fluoro-L-DOPA (18F-30M-DOPA) in the brain from the circulation is responsible for most of the nonspecific background during 18F-DOPA positron emission tomography scanning. To increase the sensitivity of 18F-DOPA for imaging presynaptic dopamine systems, we took advantage of 18F-30M-DOPA's rapid clearance from the brain (T1/2 approximately 15-20 min). The infusion of the unlabeled amino acid L-phenylalanine, starting 75 min after 18F-DOPA administration, prevents 18F-30M-DOPA entrance into the brain through competition at the large amino acid transport system of the blood brain barrier. This method produces high specific-to-nonspecific contrast images of 18F accumulation beginning 15-30 min after onset of amino acid infusion and better sensitivity to small changes in 18F-DOPA uptake while still allowing for kinetic analysis of the data in the early time points. Kinetic and anatomical data were found to be strongly correlated.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenilalanina
/
Encéfalo
/
Di-Hidroxifenilalanina
/
Intoxicação por MPTP
Limite:
Animals
Idioma:
En
Revista:
J Nucl Med
Ano de publicação:
1992
Tipo de documento:
Article