Efficient, Standard-Compliant Streaming of EHR Imagery Combining by HC120410213356

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									DICOM INTERNATIONAL
CONFERENCE & SEMINAR
April 8-10, 2008         Chengdu, China



    Efficient, Standard-Compliant Streaming of
    EHR Imagery
    Combining JPIP and WADO within an XDS-I
    Framework



                              Lev Weisfeiler
                               Aware, Inc.
                   Co-chair DICOM WG4 (Compression)
                         DICOM to JPEG liaison


                                                  www.aware.com/medical
            The need for a
standardized streaming technology
   is emerging as regions/countries
      deploy image-enabled EHR
Introduction – EHR, XDS-I

 • Many countries are implementing image-enabled EHRs
 • IHE XDS-I is an effective solution for publication and discovery
   of patient diagnostic imaging history across multiple
   enterprises
    – Physical access to data requires DICOM transfer from one PACS to
      another
        • Relatively slow due to multiple transactions and DICOM over the WAN
        • Complexities introduced from copying data between PACS
             – “ingesting foreign data” problem
        • DICOM configuration can become unmanageable in a regional setting
 • IHE XDS-I is emerging as the prevailing interoperability
   architecture
    – Some countries are promoting compliance to the IHE Profile
    – Some projects are not concerned about the compliance to standards,
      but see the profile as an effective solution to the interoperability problem
XDS - Overview

 • Objective of XDS
    – To support document sharing between enterprises in different care
      settings and organizations
 • XDS “Publish and Subscribe” paradigm
    – Create a persistent “document”… images, reports, etc.
    – Publish the document to the a “repository”
    – Register the document in an “index”
    – “Consumers” query the index to find out about documents and where
      they are stored
    – Consumers retrieve documents “on-demand” from the repository
XDS-I – Key Concepts

 • Users reference images at the “exam” (study) level
    – Users do not reference images at the “image” level


 • XDS-I needs to “publish” and “index” a document that
   represents the “exam”… not the image

 • Requires a level of abstraction, namely an image “manifest”
    – The manifest is a document with a list of pointers to the images that it
      represents
    – The manifest is a DICOM KOS object
Motivation - Image Streaming

 •   To achieve access to image data within the EHR and maintain
     acceptable performance, projects need content delivery techniques
     with streaming technology

 •   WADO is a means to address many of the DICOM related challenges in
     an image-enabled EHR
      – WADO provides HTTP-based method of access to DICOM objects
      – Consumers discover the URL to images through XDS-I and can thereby retrieve
        images via HTTP through WADO
      – Limit the use of DICOM to communications between modalities and PACS


 •   JPIP offers standardized “on-demand”, streamed access to image data
      – Streaming technology allows fast image display over lower bandwidth networks
      – Standard enables any viewing client to access data from any JPIP server
JPIP - Overview

 •   Standardized image streaming

 •   JPEG 2000, Part 9
      – ISO/IEC 15444-9
      – ITU-T Rec. T.808

 •   Included in DICOM
      – Supplement 106


 •   Efficient transmission of JPEG 2000 data over varying bandwidth
     networks
      – JPEG 2000 provides high quality, DICOM-compliant, wavelet-based image
        compression
      – JPIP is the blueprint for the best usage of JPEG 2000 functionality in a
        distributed application environment
JPIP Streaming Use Cases

 • Stack navigation of a large CT study
    – Low resolution preview
    – Full fidelity imagery available on demand


 • Large single image navigation
    – Pan/zoom region of interest at display resolution


 • Thumbnail representation for a study
    – Sub-resolution image easily extracted


 • Display by dimension
    – Random access to individual frames of a large enhanced multiframe
      object
DICOM Access Example
         1)   Patient presents at emergency room (ER)
         2)   User requests data (through XDS-I discovery and retrieve)
         3)   Copy image data via DICOM C-MOVE
         4)   Data ingestion and preparation
         5)   Image display using local PACS proprietary protocols



                                                                Consumer (ER)


XDS Registry/Repository




                                                 DICOM



                                                                                Image Manager/Archive
WADO/JPIP Access
         1) Patient presents at ER
         2) User requests data (through XDS-I discovery and retrieve)



                          XDS query (ITI-16)
                               • HTTP-SOAP with SQL text
                               • Responds with candidate documents and      Consumer (ER)
                                   associated URI

XDS Registry/Repository   XDS document retrieve (ITI-17)
                               • HTTP transaction
                               • Returns DICOM KOS object




                                                                         Image Manager/Archive
WADO/JPIP Access
         1) Patient presents at ER
         2) User requests data (through XDS-I discovery and retrieve)
         3) WADO request for image data

                          Parse the DICOM KOS “manifest”
                               • Extract the URI to series
                                                                                   Consumer (ER)
                          WADO http GET
                              • Use the URI from manifest to initiate a WADO Get
XDS Registry/Repository       • Define transfer syntax to be JPIP



                                              http GET




                                                                              Image Manager/Archive
WADO/JPIP Access
         1)   Patient presents at ER
         2)   User requests data (through XDS-I discovery and retrieve)
         3)   WADO request for image data
         4)   Image data streamed to viewing client using JPIP
                           Local PACS IM/IA supports WADO
                                 • WADO server includes JPIP server
                                                                                     Consumer (ER)
                           Stream data from JPIP enabled PACS to viewing client
                                • Viewing client supports JPIP
XDS Registry/Repository




                                                                                  Image Manager/Archive
Remote Viewing

 • Web based image viewing client
    – Access manifest (KOS) via WADO
    – Request images in manifest through WADO with a JPIP transfer syntax
    – Stream image data from JPIP enabled PACS to client
Summary - Benefits

 Combining XDS-I/WADO/JPIP

 • Standards based data discovery across multiple PACS (XDS-I)
 • Fast image access over WAN without the need for
    – DICOM configuration
    – DICOM transfer
    – Foreign data ingestion into PACS
 • All standard-compliant; no proprietary protocols
 • Leverage ubiquitous security environment
 • Client and servers can be from different vendors
Acknowledgements

 Thank you to Dr. Peter Bak for his contribution
    –   The Chair of the Pan-Canadian Standards Working Group for DI
    –   Director of architecture for DI at Canada Health Infoway
    –   Primary author of the pan-Canadian XDS-I standard
    –   Primary author of the “JPIP adoption as a pan-Canadian standard” initiative
Acronyms

 •   IHE – Integrating the Healthcare Enterprise
 •   EHR – Electronic Health Record
 •   XDS-I – Cross Enterprise Document Sharing for Imaging
 •   WADO – Web Access to DICOM Objects
 •   JPIP – JPEG 2000 Interactive Protocol
 •   PACS – Picture Archiving and Communication Systems
 •   KOS - Key Object Selection
 •   WAN – Wide Area Network

								
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