Study on volume rendering of CT slices based on ray casting

Ray casting algorithm is one important method to render CT volumes with 2D CT slices, and it can be accelerated using graphics hardware. In this paper, we developed an efficient volume rendering system based on ray casting using C++ and VTK, and designed common shading and classification transfer functions to highlight different organs/tissues of a CT volume. With this system we experimented CT volumes using CPU ray casting and GPU ray casting respectively, and then we did the same experiments on different graphics cards. The results showed that we can highlight the organs/tissues in which we are interested by setting proper transfer functions and that the rendering efficiency can be accelerated greatly using graphics cards with nVidia GPU GT220 or higher almost with the same visualization quality as that of CPU ray casting.