| Full text | |
| Author(s): Show less - |
J. Mejia
[1]
;
M.A. Reis
[1, 2]
;
A.C.C. Miranda
[1]
;
I.R. Batista
[1, 2]
;
M.R.F. Barboza
[1]
;
M.C. Shih
[1]
;
G. Fu
[3]
;
C.T. Chen
[4]
;
L.J. Meng
[5]
;
R.A. Bressan
[1, 2]
;
E. Amaro Jr
[1]
Total Authors: 11
|
| Affiliation: | [1] Hosp Israelita Albert Einstein, Inst Cerebro, Sao Paulo - Brazil
[2] Univ Fed Sao Paulo, Dept Psiquiatria, Lab Interdisciplinar Neurociencias Clin, Sao Paulo - Brazil
[3] GE Global Res, Schenectady, NY - USA
[4] Univ Chicago, Dept Radiol, Chicago, IL 60637 - USA
[5] Univ Illinois, Dept Nucl Plasma & Radiol Engn, Urbana, IL 61801 - USA
Total Affiliations: 5
|
| Document type: | Journal article |
| Source: | Brazilian Journal of Medical and Biological Research; v. 46, n. 11, p. 936-942, 2013-11-06. |
| Abstract | |
The single photon emission microscope (SPEM) is an instrument developed to obtain high spatial resolution single photon emission computed tomography (SPECT) images of small structures inside the mouse brain. SPEM consists of two independent imaging devices, which combine a multipinhole collimator, a high-resolution, thallium-doped cesium iodide [CsI(Tl)] columnar scintillator, a demagnifying/intensifier tube, and an electron-multiplying charge-coupling device (CCD). Collimators have 300- and 450-µm diameter pinholes on tungsten slabs, in hexagonal arrays of 19 and 7 holes. Projection data are acquired in a photon-counting strategy, where CCD frames are stored at 50 frames per second, with a radius of rotation of 35 mm and magnification factor of one. The image reconstruction software tool is based on the maximum likelihood algorithm. Our aim was to evaluate the spatial resolution and sensitivity attainable with the seven-pinhole imaging device, together with the linearity for quantification on the tomographic images, and to test the instrument in obtaining tomographic images of different mouse organs. A spatial resolution better than 500 µm and a sensitivity of 21.6 counts·s-1·MBq-1 were reached, as well as a correlation coefficient between activity and intensity better than 0.99, when imaging 99mTc sources. Images of the thyroid, heart, lungs, and bones of mice were registered using 99mTc-labeled radiopharmaceuticals in times appropriate for routine preclinical experimentation of <1 h per projection data set. Detailed experimental protocols and images of the aforementioned organs are shown. We plan to extend the instrument's field of view to fix larger animals and to combine data from both detectors to reduce the acquisition time or applied activity. (AU) | |
| FAPESP's process: | 08/08902-5 - Radiotracers of Molecular Imaging in dopamine and serotonin receptors in animal model research in vivo SPECT compared with in vivo binding assay and ex vivo autoradiography. |
| Grantee: | Marilia Alves dos Reis |
| Support Opportunities: | Scholarships in Brazil - Master |