Data/hora: 09/06/2024 09:33:43

Provedor de dados: 	56	
País: 	Brazil	
Título: 	A clinical gamma camera-based pinhole collimated system for high resolution small animal SPECT imaging	
Autores: 	Mejia,J.; Galvis-Alonso,O.Y.; Castro,A.A.de; Braga,J.; Leite,J.P.; Simões,M.V.	
Data: 	2010-12-01	
Ano: 	2010	
Palavras-chave: 	Pinhole collimator; SPECT; Small animal organs; Maximum likelihood; Instrumentation; Image processing.	
Resumo: 	The main objective of the present study was to upgrade a clinical gamma camera to obtain high resolution tomographic images of small animal organs. The system is based on a clinical gamma camera to which we have adapted a special-purpose pinhole collimator and a device for positioning and rotating the target based on a computer-controlled step motor. We developed a software tool to reconstruct the target’s three-dimensional distribution of emission from a set of planar projections, based on the maximum likelihood algorithm. We present details on the hardware and software implementation. We imaged phantoms and heart and kidneys of rats. When using pinhole collimators, the spatial resolution and sensitivity of the imaging system depend on parameters such as the detector-to-collimator and detector-to-target distances and pinhole diameter. In this study, we reached an object voxel size of 0.6 mm and spatial resolution better than 2.4 and 1.7 mm full width at half maximum when 1.5- and 1.0-mm diameter pinholes were used, respectively. Appropriate sensitivity to study the target of interest was attained in both cases. Additionally, we show that as few as 12 projections are sufficient to attain good quality reconstructions, a result that implies a significant reduction of acquisition time and opens the possibility for radiotracer dynamic studies. In conclusion, a high resolution single photon emission computed tomography (SPECT) system was developed using a commercial clinical gamma camera, allowing the acquisition of detailed volumetric images of small animal organs. This type of system has important implications for research areas such as Cardiology, Neurology or Oncology.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2010001200004	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X2010007500128	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.43 n.12 2010	
Fonte: 	info:eu-repo/semantics/openAccess