DICOM INTERNATIONAL 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

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 –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 Image Manager/Archive Consumer (ER) XDS Registry/Repository DICOM

WADO/JPIP Access 1)Patient presents at ER 2)User requests data (through XDS-I discovery and retrieve) Image Manager/Archive Consumer (ER) XDS Registry/Repository XDS query (ITI-16) HTTP-SOAP with SQL text Responds with candidate documents and associated URI XDS document retrieve (ITI-17) HTTP transaction Returns DICOM KOS object

WADO/JPIP Access 1)Patient presents at ER 2)User requests data (through XDS-I discovery and retrieve) 3)WADO request for image data Image Manager/Archive Consumer (ER) XDS Registry/Repository http GET Parse the DICOM KOS “manifest” Extract the URI to series WADO http GET Use the URI from manifest to initiate a WADO Get Define transfer syntax to be JPIP

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 Image Manager/Archive Consumer (ER) XDS Registry/Repository Local PACS IM/IA supports WADO WADO server includes JPIP server Stream data from JPIP enabled PACS to viewing client Viewing client supports JPIP

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