D.P. Scraggs

Development of the ProSPECTus semiconductor Compton camera for medical imaging

The ProSPECTus project is the development of a prototype semiconductor Compton camera for use in nuclear medical imaging applications. The proposed system has the potential to improve the sensitivity of conventional mechanically col-limated Single Photon Emission Computed Tomography (SPECT) systems through the use of electronic collimation techniques. In addition, the use of compatible semiconductor technology within a Magnetic Resonance Imaging (MRI) system could potentially lead to simultanous SPECT/MRI data acquisition. This paper outlines the consideration of key design features for the new system. Such design factors include the geometrical setup, suitable energy and position resolution values for the detectors and the ability of the system to function in a magnetic field. The ProSPECTus protoype imaging system will now be built according to optimised specifications.

Prospectus: Development of a Compton Camera for Medical Imaging

Single Photon Emission Computed Tomography (SPECT) is an established method of studying physiological functions. However, novel gamma-ray Compton camera systems which provide electronic collimation have the potential to greatly improve the sensitivity of this technique. Compton cameras have been employed in high energy applications but have not yet been fully implemented for clinical applications at low energies. This paper describes the optimization of imaging efficiency for the ProSPECTus medical imaging Compton camera system with 99mTc. Experimental factors which degrade the image quality will also be assessed and quantified.

Compton imaging with a planar semiconductor system using pulse shape analysis

Homeland security agencies have a requirement to locate and identify nuclear material. Compton cameras [1, 2] offer a more efficient method of gamma-ray detection than collimated detector systems. The resolution of the interaction positions within the detectors greatly influences the accuracy of a reconstructed Compton image. Utilizing digital electronics and applying pulse shape analysis [3] allows the spatial resolution to be enhanced beyond the pixel granularity in three dimensions. Analytically reconstructed Compton images from a range of radiation sources shall be presented with and without pulse shape analysis showing the improvements gained along with a discussion of our analysis methods.

First Results with TIGRESS and Accelerated Radioactive Ion Beams from ISAC: Coulomb Excitation of 20,21,29Na

The TRIUMF‐ISAC Gamma‐Ray Escape Suppressed Spectrometer (TIGRESS) is a state‐of‐the‐art γ‐ray spectrometer being constructed at the ISAC‐II radioactive ion beam facility at TRIUMF. TIGRESS will be comprised of twelve 32‐fold segmented high‐purity germanium (HPGe) clover‐type γ‐ray detectors, with BGO/CsI(Tl) Compton‐suppression shields, and is currently operational at ISAC‐II in an early‐implementation configuration of six detectors. Results have been obtained for the first experiments performed using TIGRESS, which examined the A = 20, 21, and 29 isotopes of Na by Coulomb excitation.