Revista mexicana de física
versão impressa ISSN 0035-001X
ALVA-SANCHEZ, H. et al. Prototipo de microtomógrafo por emisión de positrones: resolución espacial y estudios metabólicos. Rev. mex. fis. [online]. 2010, vol.56, n.2, pp. 175-182. ISSN 0035-001X.
During the past 4 years, the Medical Physics and Dosimetry Group at the Instituto de Física, UNAM, has developed a positron emission tomography prototype for small-animal imaging (microPET). The system is composed of pixelated, cerium-doped lutetium yttrium oxyort-hosilicate scintillation crystal arrays coupled to position-sensitive photomultiplier tubes. Detector electronic signals are processed by nuclear instrumentation modules and are digitized by a multichannel data acquisition board. The tomographic reconstruction is performed by filtered backprojection from a set of distortion- and nonuniformity- corrected projections taken at different angles. In this work, the reconstructed spatial resolution was evaluated from the line spread function with a mean value of 2.36 ± 0.44 mm. In addition, the first metabolic studies of 30 g, healthy mice, injected with 18F labeled fluorodeoxyglucose and sodium fluoride are reported. They display normal glucose uptake and skeletal structure, respectively. The microPET can be a useful tool for radiation detector physics research and its applications in nuclear medicine.
Palavras-chave : Positron emission tomography; PET; spatial resolution; small-animal.