Abstract
The purpose of this work is to simulate the application of dual photons computed tomography (DuPECT) in animal study. The detector of the micoPET 、multi-pinhole collimator and the isotope 111In were used in the DuPECT method. It is expected to alter the problem that the isotopes used in PET must be generated from the cyclotron (high costs and short half-life) and to obtain higher resolution. 111In disintegrates by >99.99% and then emits two γ photons with 171keV and 245keV energy. As a result of both the multi-pinhole collimator which could collimate the emitted photons and the coincidence circuit of the PET system which could obtain the coincidence, we can use the two coincidence events to each connect to the pinholes to obtain two lines which can intersect to a point but not a line of response (LOR) like microPET does. Each coincidence can use the above method to obtain one intersection which is also the position of decay. We devised 5 experiments in this paper (varies pinhole size、different position of the point source、uniformity、quantification and attenuation correction) to construct the geometry of the DuPECT system and to test the system. The results showed that the resolution in the central field-of-view is around 1.8 mm, the sensitivity is 0.0295%, the uniformity is around 6.3% and the distortion is more serious as the source farther from the CFOV. Due to the random effect and the artifact, the quantification is not precise. The simulation proved that the concept of DuPECT method is feasible if only the isotope would emits two photons with distinct energy. Both the resolution and the sensitivity are not as good as we expected. There are still many problems need to be solved, nevertheless, DuPECT is in its initial stage so that many things need to be done in the future.