Towards a grid system for medical image reconstruction

This paper presents an experimental grid system - the MIRGrid-which enables transparent usage of high- performance computers for medical image reconstruction. MIR-grid provides a comfortable way to perform time-consuming iterative image reconstructions on interconnected high-performance computers; it covers the whole imaging workflow: from reading the raw data acquired by the scanner, over user-transparent parallel reconstruction to visualization. The system is able to perform and monitor parallel reconstructions on different kinds of parallel architectures with shared and distributed memory, as well as combinations of both. In order to optimally distribute the reconstructions among the high-performance computers, we estimate parallel reconstruction time by using a previously developed performance model. Additionally to traditional 3D imaging, the system seamlessly integrates dynamic (4D) and gated studies. The system optimizes parallel 4D reconstruction time by partitioning dynamic and gated reconstructions into independent 3D sub- reconstructions that are computed simultaneously on several high- performance computers.