
The research group ASTRA, part of the Vision Lab of the University of Antwerp, focuses on the development of new computational methods for tomography. Tomography is a technique used in medical scanners to create three-dimensional images of the internal organs of patients, based on a large number of X-ray photos that are acquired over a range of angles. ASTRA develops new reconstruction techniques that lead to better reconstruction quality than classical methods.
Tomography in medical scanners creates three-dimensional images of the internal organs of patients, based on numerous X-ray photos a range of angles. As these 3D images can be quite large, advanced reconstruction techniques can sometimes require weeks of computation time on a regular PC. Fortunately, the computations can be carried out in parallel, for example using a cluster consisting of hundreds of PC's. Employing a large cluster his quite expensive, is not always available, takes a lot of space and requires considerable maintenance.
To be able to perform our computations without using a cluster, ASTRA scientists developed software for reconstructing 3D images with the aid of 3D graphics cards, that are supposed to be used for playing 3D games. In fact, graphics cards are highly suitable for tomography computations. Each graphics processor (GPU) contains 128 small subprocessors that can all work in parallel. By appropriate programming of the GPUs, many calculations can be performed simultaneously.
For their most demanding computations tasks, they developed the FASTRA: a desktop superPC, which contains four dual-GPU graphics cards. Having eight graphics processors work in parallel allows this system to perform as fast as 350 modern processor cores for tomography computations, reducing the reconstruction times from several weeks (on a normal PC) to hours.
The Vision Lab is now planning to build a cluster of such systems, which will allow for real-time reconstruction of large 3D volumes. In a May posting on the site is a job opening for a Software engineer in image processing where research involves the implementation of new image processing algorithms for industrial applications.
Web: http://visielab.ua.ac.be/
Source: ASTRA -- http://fastra.ua.ac.be