A Compton camera prototype has been developed using a pixelated CZT detector with 4-by-4 pixels.Signals of the detector are read out by a VASTAT ASIC that is controlled by a self-developed DAQ board. The DAQ software ...A Compton camera prototype has been developed using a pixelated CZT detector with 4-by-4 pixels.Signals of the detector are read out by a VASTAT ASIC that is controlled by a self-developed DAQ board. The DAQ software is developed using LabVIEW, and the offline Compton imaging codes are written in C++. The prototype has been successfully calibrated, and its capabilities for source detection, spectroscopy, and Compton imaging have been demonstrated using a Cs-137 source.The angular resolution of the 662 keV line is 36° FWHM for the simple back-projection method and 9.6° FWHM for the MLEM reconstruction method. The system is ready to be extended to 11-by-11 pixels in the future, and a better imaging quality can be expected due to the better relative position resolution.展开更多
Two new Compton Scatter Tomography modalities, which are aimed at imaging hidden structures in bulk matter for industrial non-destructive control (or testing) and for medical diagnostics are shown to be based on the s...Two new Compton Scatter Tomography modalities, which are aimed at imaging hidden structures in bulk matter for industrial non-destructive control (or testing) and for medical diagnostics are shown to be based on the solutions of a special class of Chebyshev integral transforms. Besides their remarkable analytic properties, they can be inverted by existing methods which lend themselves nicely to numerical treatment and provide convergent, stable and fast computation algorithms. The existence of explicit inversion formulas implies that viable new imaging techniques can be developed, which may take over the current ones in a near future.展开更多
文摘A Compton camera prototype has been developed using a pixelated CZT detector with 4-by-4 pixels.Signals of the detector are read out by a VASTAT ASIC that is controlled by a self-developed DAQ board. The DAQ software is developed using LabVIEW, and the offline Compton imaging codes are written in C++. The prototype has been successfully calibrated, and its capabilities for source detection, spectroscopy, and Compton imaging have been demonstrated using a Cs-137 source.The angular resolution of the 662 keV line is 36° FWHM for the simple back-projection method and 9.6° FWHM for the MLEM reconstruction method. The system is ready to be extended to 11-by-11 pixels in the future, and a better imaging quality can be expected due to the better relative position resolution.
文摘Two new Compton Scatter Tomography modalities, which are aimed at imaging hidden structures in bulk matter for industrial non-destructive control (or testing) and for medical diagnostics are shown to be based on the solutions of a special class of Chebyshev integral transforms. Besides their remarkable analytic properties, they can be inverted by existing methods which lend themselves nicely to numerical treatment and provide convergent, stable and fast computation algorithms. The existence of explicit inversion formulas implies that viable new imaging techniques can be developed, which may take over the current ones in a near future.
