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Full-Text Articles in Engineering
Characterisation Of A Cobalt-60 Small-Beam Animal Irradiator Using A Realtime Silicon Pixelated Detector, C Porumb, Jocelyn Davies, Vladimir Perevertaylo, Anatoly B. Rosenfeld, Marco Petasecca
Characterisation Of A Cobalt-60 Small-Beam Animal Irradiator Using A Realtime Silicon Pixelated Detector, C Porumb, Jocelyn Davies, Vladimir Perevertaylo, Anatoly B. Rosenfeld, Marco Petasecca
Faculty of Engineering and Information Sciences - Papers: Part A
The paper presents a study performed by the Centre for Medical Radiation Physics (CMRP) using a high spatial and temporal resolution silicon pixelated detector named MagicPlate- 512. The study focuses on the characterisation of three pencil beams from a low-dose rate, 6 TBq, cobalt-60 source, in terms of percentage depth dose, beam profiles, output factor and shutter timing. Where applicable, the findings were verified against radiochromic EBT3 film and ionization chambers. It was found that the results of the MagicPlate-512 and film agreed within 0.9 mm for penumbra and full-width at half-maximum measurements of the beam profiles, and within 0.75% …
Unified Geometric Calibration And Image Registration For Detached Small Animal Spect/Ct, Xuezhu Zhang, Fangfu Chen, Yongping Li, Qin Wei, Yujin Qi
Unified Geometric Calibration And Image Registration For Detached Small Animal Spect/Ct, Xuezhu Zhang, Fangfu Chen, Yongping Li, Qin Wei, Yujin Qi
Faculty of Engineering and Information Sciences - Papers: Part A
The aim of this study is to develop a unified optimization method to estimate the complete parameters about geometric calibration of system misalignment for both cone-beam CT and pinhole SPECT, and parameters about coordinate transformation of image registration for these detached systems. The uniform projection equations are derived for both cone-beam and pinhole imaging geometry. Complete geometric parameters are estimated by point object phantom with a priori relative position information. The cost function is structured as the least-squares about residual error. The implementation of nonlinear estimation utilizes the Powell method so as to constrain the optimization problem of this study …
Development And Characterization Of A High-Resolution Microspect System For Small-Animal Imaging, Yujin Qi, Benjamin Tsui, Yuchuan Wang, Brian Yoder, R Wojcik, S Majewski, A G Weisenberger
Development And Characterization Of A High-Resolution Microspect System For Small-Animal Imaging, Yujin Qi, Benjamin Tsui, Yuchuan Wang, Brian Yoder, R Wojcik, S Majewski, A G Weisenberger
Faculty of Engineering and Information Sciences - Papers: Part A
We developed a high-resolution microSPECT system and investigated its performance characteristics for small animal imaging. The microSPECT system consists of a stationary compact gamma camera with interchangeable pinhole and parallel-hole collimators and vertical object rotation mechanism. The modular camera is based on a pixellated NaI(Tl) crystal array with 1.2 mm pixel size and 1.4 mm pixel pitch coupled to a 5” diameter Hamamatsu R3292 PSPMT. The pinhole collimator has a 10cm focal length fitted with keel-edge pinhole apertures with diameters of 1.0, 1.5 and 2.0 mm. The system performance was characterized by the measurements of the point source response function …
Optimized Collimator Designs For Small Animal Spect Imaging With A Compact Gamma Camera, Yujin Qi
Optimized Collimator Designs For Small Animal Spect Imaging With A Compact Gamma Camera, Yujin Qi
Faculty of Engineering and Information Sciences - Papers: Part A
The aim of this study to design optimized pinhole and parallel-hole collimators for the development of a high-resolution microSPECT system using a compact pixelleted scintillation detector. The detector has a field-of-view of 11 cm with pixellated crystal elements of 1.0 mm pixel size and 1.12 mm pixel pitch. The relative resolution and sensitivity advantages of pinhole and parallel-hole collimators for mice and rats imaging were investigated using analytic formulations and Monte Carlo simulations. The optimized collimator designs were obtained by maximizing the system detection efficiency for a given object resolution. The collimator designs were optimized for 140 keV incident gamma …