| Scintigraphy, also known as nuclear imaging, is the process of imaging an object that has been labeled with a radioactive material. A novel technique employing polycapillary optics for very high - resolution scintigraphy is presented. The small channel size and angular selectivity of polycapillary optics allow them to act as multiple-hole collimators and be used with high - resolution detectors. The ability of the optics to work with high resolution detectors allow the system to discriminate against scatter, thus negating the need for energy sensitive detectors, which are known to have poor resolution. Therefore the use of polycapillary optics presents the opportunity to both reject scatter and increase resolution. Measurements were performed to determine the effects of increasing source - to - detector distances and optic - to - detector distances compared to those used in previous works, as well as increasing the length of the optics. The images exhibited promising signal - to -background rations while still displaying sub - millimeter resolutions, even with large amounts of tissue - equivalent material in place. Lastly, a Markov Chain Monte Carlo algorithm was developed to estimate the resolution of images, determine parameters of the brachytherapy seeds employed to simulate patient dose, and determine theoretical signal - to - background ratios, all of which showed fair agreement with experimental results. |
