A Reliable DICOM Transfer Grid Service Based on Petri Net Workflows

Medical grid networks typically deal with extremely sensitive information and therefore require a special diligence in terms of security and reliability. This holds especially true in Medical Imaging, which is why the medical community long established DICOM (Digital Imaging and Communication in Medicine), a world-wide imaging and communication standard for secure and reliable data interchange. Most healthgrid projects today use DICOM with a combination of GridFTP and the Reliable-File-Transfer (RFT) webservice. Due to the multiple protocols and services involved, this solution is not ideally suited in terms of reliability or fault-tolerance. The proposed solution in this paper replaces the GridFTP combination by an end- to-end Grid-enhanced DICOM implementation and models the GridDICOM transfers as complex, Petri-Nets-based workflows. Based on these workflows, a respective workflow engine can autonomously and reliably control transfers including complex fault recovery and optimized routing strategies. A first prototype of the service, the components, and the respective workflows have been developed and successfully tested in MediGRID, the German grid network for life-sciences.