title: A DICOM-based 2nd generation Molecular Imaging Data Grid implementing the IHE XDS-i integration profile.
abstract: OBJECTIVE
  A Molecular Imaging Data Grid (MIDG) was developed to address current informatics challenges in archival, sharing, search, and distribution of preclinical imaging studies between animal imaging facilities and investigator sites. This manuscript presents a 2nd generation MIDG replacing the Globus Toolkit with a new system architecture that implements the IHE XDS-i integration profile. Implementation and evaluation were conducted using a 3-site interdisciplinary test-bed at the University of Southern California.
  
  
  METHODS
  The 2nd generation MIDG design architecture replaces the initial design's Globus Toolkit with dedicated web services and XML-based messaging for dedicated management and delivery of multi-modality DICOM imaging datasets. The Cross-enterprise Document Sharing for Imaging (XDS-i) integration profile from the field of enterprise radiology informatics was adopted into the MIDG design because streamlined image registration, management, and distribution dataflow are likewise needed in preclinical imaging informatics systems as in enterprise PACS application. Implementation of the MIDG is demonstrated at the University of Southern California Molecular Imaging Center (MIC) and two other sites with specified hardware, software, and network bandwidth.
  
  
  RESULTS
  Evaluation of the MIDG involves data upload, download, and fault-tolerance testing scenarios using multi-modality animal imaging datasets collected at the USC Molecular Imaging Center. The upload, download, and fault-tolerance tests of the MIDG were performed multiple times using 12 collected animal study datasets. Upload and download times demonstrated reproducibility and improved real-world performance. Fault-tolerance tests showed that automated failover between Grid Node Servers has minimal impact on normal download times.
  
  
  CONCLUSIONS
  Building upon the 1st generation concepts and experiences, the 2nd generation MIDG system improves accessibility of disparate animal-model molecular imaging datasets to users outside a molecular imaging facility's LAN using a new architecture, dataflow, and dedicated DICOM-based management web services. Productivity and efficiency of preclinical research for translational sciences investigators has been further streamlined for multi-center study data registration, management, and distribution.
authors.affiliation: Image Processing and Informatics Laboratory, Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, 734 West Adams Blvd., Los Angeles, CA 90089, USA. jasperle@usc.edu
authors.forename: Jasper
authors.initials: J
authors.lastname: Lee
authors.forename: Jianguo
authors.initials: J
authors.lastname: Zhang
authors.forename: Ryan
authors.initials: R
authors.lastname: Park
authors.forename: Grant
authors.initials: G
authors.lastname: Dagliyan
authors.forename: Brent
authors.initials: B
authors.lastname: Liu
authors.forename: H K
authors.initials: HK
authors.lastname: Huang
mesh_terms: D003195:Computer Communication Networks; D003199:Computer Systems; D008491:Medical Informatics Applications; D057054:Molecular Imaging / Q000295:instrumentation*; D018511:Systems Integration