XDS-I Using XDS.b Technology - Detailed Proposal

1. Proposed Workitem: Maintain Consistency of XDS-I with the latest XDS Specification (XDS.b) - Detailed Proposal

• Proposal Editor: Paul Seifert
• Editor: TBD
• Date: N/A (Wiki keeps history)
• Version: N/A (Wiki keeps history)
• Domain: Radiology

Summary

<Summarize in a few lines the existing problem . E.g. "It is difficult to monitor radiation dose for individual patients and almost impossible to assemble and compare such statistics for a site or a population.">

<Demonstrate in a line or two that the key integration features are available in existing standards. E.g. "DICOM has an SR format for radiation dose events and a protocol for exchanging them.">

<Summarize in a few lines how the problem could be solved. E.g. "A Radiation Dose profile could require compliant radiating devices to produce such reports and could define transactions to actors that collect, analyze and present such information.">

<Summarize in a line or two market interest & available resources. E.g. "Euratom and ACR have published guidelines requiring/encouraging dose tracking. Individuals from SFR are willing to participate in Profile development.">

<Summarize in a line or two why IHE would be a good venue to solve the problem. E.g. "The main challenges are dealing with the chicken-and-egg problem and avoiding inconsistent implementations.">

2. The Problem

The current XDS-I profile is based upon technical solution (and technologies) specified in what is now called ITI's XDS.a Integration Profile. Subsequent to the final text publication of XDS-I, the ITI domain has published the specification of XDS.b which updates the technology(ies) used in the XDS profile while maintaining semantic equivalence. For a list of the differences, see ITI's XDS.b Supplement at: XDS.b Supplement

While it is technically possible to have hybrid environments (with a mix of XDS.a and XDS.b based systems), it complicates the deployment and integration activity by requiring "broker" type systems to bridge the gap between the XDS.a and XDS.b technologies. Since IHE's goal is to simplify integration of healthcare systems, it seems counter to that goal to NOT create an updated version of XDS-I that is based on the XDS.b specification.

3. Key Use Case

The original XDS-I use cases remain the same. The purpose of this change in technologies is to maintain close alignment between XDS-I and XDS (XDS.b in this case) allowing for simpler deployments. Furthermore, clear direction and acceptance of an XDS.b-based version of XDS-I will help vendors to focus their efforts on a single technology, since XDS.b is being "pushed" more heavily by the ITI domain.

4. Standards & Systems

The actor most affected by this change is the Imaging Document Source (XDS-I), and the standards involved in this profile are the same as those identified for XDS.b:

• ebRIM - OASIS/ebXML Registry Information Model v3.0
• ebRS - OASIS/ebXML Registry Services Specifications v3.0
• SOAP12 - SOAP 1.2 Recommendation [1]
• SOAP11 - SOAP 1.1 Note [2]
• WSDL11 - WSDL 1.1 Note [3]
• MTOM - SOAP Message Transmission Optimization Mechanism [4]

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This Delta Proposal Template is for expanding copy of a Brief Proposal into a Detailed Proposal. This template and the Detailed Proposal Template should be updated in sync.

• Paste this text into a copy of your Brief Proposal
• Move the Summary section to the end of Section 1
• Expand details in the Use Case Section
• Distribute material in the Discussion Section into the other bottom sections.

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5. Technical Approach

<This section can be very short but include as much detail as you like. The Technical Committee will flesh it out when doing the effort estimation.>

<Outline how the standards could be used/refined to solve the problems in the Use Cases. The Technical Committee will be responsible for the full design and may choose to take a different approach, but a sample design is a good indication of feasibility.>

<If a phased approach would make sense indicate some logical phases. This may be because standards are evolving, because the problem is too big to solve at once, or because there are unknowns that won’t be resolved soon.>

Existing actors

<Indicate what existing actors could be used or might be affected by the profile.>

New actors

<List possible new actors>

Existing transactions

<Indicate how existing transactions might be used or might need to be extended.>

New transactions (standards used)

<Describe possible new transactions (indicating what standards would likely be used for each. Transaction diagrams are very helpful here. Feel free to go into as much detail as seems useful.>

Impact on existing integration profiles

<Indicate how existing profiles might need to be modified.>

New integration profiles needed

<Indicate what new profile(s) might need to be created.>

Breakdown of tasks that need to be accomplished

<A list of tasks would be helpful for the technical committee who will have to estimate the effort required to design, review and implement the profile.>

6. Support & Resources

<List groups that have expressed support for the proposal and resources that would be available to accomplish the tasks listed above.>

7. Risks

The question: "If/ when (and how) to update XDS-I to leverage 'XDS.b technology'?" was raised in the past (shortly after the TI publication of XDS.b by ITI), and at the time the Radiology Committee's position was: "let's wait and see how stable the XDS.b specification is before doing anything."

• The following feedback was solicited and recently received from Lynn Felhofer (IHE Project Manager - MIR) on the question of XDS.b stability:

  "We had widespread adoption of XDS.b at Chicago (17 Consumers, 5 Registries, 7 Repositories, 14 Sources); also for Oxford (13 Consumers, 14 Registries, 17 Repositories, 12 Sources)."

  "In Chicago, the vast majority of systems tested successfully. The biggest struggle we had in the fall was that the NIST tools were being developed in parallel with vendors doing their implementation. This is because ITI finishes their specs in Aug, leaving no time for advanced tool development. So, all of the implementers learned together, and Bill released updates to the toolkit as vendors found problems. If you subscribe to the XDS implementers google group, you witnessed this churn. That has largely subsided now, and I think the tools are pretty stable."

  "The other caveat is that we really just tested the 'simple case' for XDS.b this year (doc submit/retrieve). Features like Folder Management, and Document Lifecycle (append, replace) aren't tested in the tools and were made optional connectathon tests for this year. Next year they will be required."

  "Overall, XDS.b testing went better than I anticipated it would when the profile was finished back in August. My personal opinion would be the profile is solid enough to consider it as a base for XDS-I. This fall's experience did result in several CPs against XDS.b; the TF documentation will remain a bit of a challenge for implementers to assimilate until those CPs are incorporated into the profile. Steve and I tried to address the documentation problem a bit by compiling a page that points to all of the pieces of documentation needed for XDS.b (and other profiles):"

• http://ihewiki.wustl.edu/wiki/index.php/Summary_Of_IHE_Technical_Requirements

8. Open Issues

<Point out any key issues or design problems. This will be helpful for estimating the amount of work and demonstrates thought has already gone into the candidate profile.>

9. Tech Cmte Evaluation

<The technical committee will use this area to record details of the effort estimation, etc.>

Effort Evaluation (as a % of Tech Cmte Bandwidth):

• 35% for ...

Responses to Issues:

See italics in Risk and Open Issue sections

Candidate Editor:

TBA