9 research outputs found
New MRI, 18F-DOPA and 11C-(+)-alpha-dihydrotetrabenazine templates for Macaca fascicularis neuroimaging: advantages to improve PET quantification
Normalization of neuroimaging studies to a stereotaxic space allows the utilization of standard volumes of
interest (VOIs) and voxel-based analysis (SPM). Such spatial normalization of PET and MRI studies requires a
high quality template image. The aim of this study was to create new MRI and PET templates of 18F-DOPA
and 11C-(+)-α-dihydrotetrabenazine (11C-DTBZ) of the Macaca fascicularis brain, an important animal
model of Parkinson's disease. MRI template was constructed as a smoothed average of the scans of 15
healthy animals, previously transformed into the space of one representative MRI. In order to create the PET
templates, 18F-DOPA and 11C-DTBZ PET of the same subjects were acquired in a dedicated small animal PET
scanner and transformed to the created MRI template space. To validate these templates for PET
quantification, parametric values obtained with a standard VOI-map applied after spatial normalization to
each template were statistically compared to results computed using individual VOIs drawn for each animal.
The high correlation between both procedures validated the utilization of all the templates, improving the
reproducibility of PET analysis. To prove the utility of the templates for voxel-based quantification, dopamine
striatal depletion in a representative monkey treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP) was assessed by SPM analysis of 11C-DTBZ PET. A symmetric reduction in striatal 11C-DTBZ uptake
was detected in accordance with the induced lesion. In conclusion, templates of M. fascicularis brain have
been constructed and validated for reproducible and automated PET quantification. All templates are
electronically available via the internet
New MRI, 18F-DOPA and 11C-(+)-alpha-dihydrotetrabenazine templates for Macaca fascicularis neuroimaging: advantages to improve PET quantification
Normalization of neuroimaging studies to a stereotaxic space allows the utilization of standard volumes of
interest (VOIs) and voxel-based analysis (SPM). Such spatial normalization of PET and MRI studies requires a
high quality template image. The aim of this study was to create new MRI and PET templates of 18F-DOPA
and 11C-(+)-α-dihydrotetrabenazine (11C-DTBZ) of the Macaca fascicularis brain, an important animal
model of Parkinson's disease. MRI template was constructed as a smoothed average of the scans of 15
healthy animals, previously transformed into the space of one representative MRI. In order to create the PET
templates, 18F-DOPA and 11C-DTBZ PET of the same subjects were acquired in a dedicated small animal PET
scanner and transformed to the created MRI template space. To validate these templates for PET
quantification, parametric values obtained with a standard VOI-map applied after spatial normalization to
each template were statistically compared to results computed using individual VOIs drawn for each animal.
The high correlation between both procedures validated the utilization of all the templates, improving the
reproducibility of PET analysis. To prove the utility of the templates for voxel-based quantification, dopamine
striatal depletion in a representative monkey treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP) was assessed by SPM analysis of 11C-DTBZ PET. A symmetric reduction in striatal 11C-DTBZ uptake
was detected in accordance with the induced lesion. In conclusion, templates of M. fascicularis brain have
been constructed and validated for reproducible and automated PET quantification. All templates are
electronically available via the internet
Comparação entre dois protocolos para obtenção de plasma rico em plaquetas, em cães
Avaliaram-se dois protocolos para a produção de plasma rico em plaquetas (PRP) com o sangue de 20 cães adultos. Foram coletados três frascos de sangue em que um deles foi usado para produção do PRP por meio do protocolo A - centrifugação única a 1200rpm/10min -, o outro para fabricação do PRP pelo protocolo B - primeira centrifugação a 1200rpm/10min e a segunda centrifugação a 1600rpm/10min - e o terceiro para realização da contagem plaquetária no sangue total, que serviu de parâmetro para os valores alcançados no PRP. O protocolo no qual foi possível alcançar maior concentração plaquetária foi testado em outros 20 cães para avaliar sua reprodutibilidade. Constatou-se que o protocolo B resultou em maior plaquetometria em 100% das amostras e concluiu-se ser ele eficiente para a produção do PRP em cães