Abstract
Since X-ray CT examination is one of the leading procedures in health clinics, actual X-ray CT equipments are used for testing and training in educational institutions that train medical radiological technicians. However, a real-life X-ray CT equipment is large and has a complicated internal structure, so the testing and training curriculum is limited for helping students comprehend the electrical and image analysis principles of the equipment, and it is also necessary to consider the dangers of exposure to X-rays. For that reason, there is demand for a simpler educational equipment that achieves such objectives. We therefore construct a testing equipment using optical heterodyne interferometry, which offers superior directionality and selectivity of the rectilinear-light component, with the objective of developing a simulated CT equipment system for educational purposes using laser light. By using this prototype simulated CT equipment, the students doing the tests can visually confirm the beam during real-life scanning, and can also avoid exposure to X-rays. Since it is also possible to create a simulated CT image from image reconstruction algorithms used in X-ray CT, based on transmitted light strength data that is obtained, we can expect that this equipment will be highly effective as an educational tool. This paper reports on the detection by optical heterodyne interferometry of weak rectilinear light that passes through phantoms fabricated by the scattering solution and the creation of a simulated CT image from beat signal strength. We also constructed a system that can reconstruct sectional images in the heightwise direction, to create a three-dimensional image. We show the effect of the surface texture of the phantom container on the simulated CT image by the use of light.
