Part 3: Answers to XDS/XDS-I webinar audience questions

Here are the last of the questions from the webinar. Let us know if you have more.

11.) Q: How would one publish a list of studies that are stored on a lagacy PACS to an XDS registry

A: This is a batch job. More sophisticated methods could be developed in the source actor to query the PACS for all priors as new studies are published. This would balance the performance hit over time.

12.) Q: Is it possible to make this an automated process. So radiologists are not required to log on and request data?

A: Definitely. But that is a function of the PACS. In the Canadian projects we have stipulated to the Consuming PACS vendors that they need to expand their pre-fetch algorithms to include discovery and retrieval from the XDS domain

13.) Q: Have you run into trouble credentialing multiple facilities (who are competitors) to see and control each other's information?

A: Not in Canada as we are a publicly funded health system.

14.) Q: How do you get multiple RIS systems to utilize a EMPI? What do you do with duplicates/typos?

A: Integration with the EMPI is from the “registration” service. This is typically in the HIS (ADT function) but could also be as part of a standalone RIS – assuming it support broadcasting HL7 ADT messages. There are two stages to EMPI integration:

1. Passive integration – in this case you send ADT information to the EMPI and do not get anything back in the ADT. When you query the EMPI from your source/consumer actor, you get the global ID. In this scenario the registration staff are unable to reconcile information at the time of registration so you are dependent on the medical records team managing the quality of data in the EMPI.

2. Active Integration – in this case the registration person can check the patients credentials in the EMPI and make corrections as needed. As such, reconciliation happens at the time of patient registration and off-loads the burden on the medical records team that manages the EMPI.

15.) Q: Peter, is XDS repository contributing to an EPR in Canada?

A: I am not quite sure of the question. Let me say that we have not integrated an XDS-I consumer into an EHR or EMR application yet. This is something that will be implemented in Ontario shortly.

16.) Q: What’s your thought on NHIH CONNECT for connecting different entities?

A: Need to review CONNECT architecture and services…not overly familiar with this yet!

17.) Q: Which PACS vendors are XDS compliant to date?

A: Check IHE Connectathon results for XDS-I actor compliance.

18.) Q: Cardiology applications?

A: Cardiology information is (for the most part) DICOM so it can be added to the XDS-I repository. However, I am not familiar with any Cardiology PACS systems that are XDS compliant yet.

19.) Q: Would like to hear more about the on-demand viewing. Would like to hear more about when new versions of images may be created by someone viewing an image on-demand or otherwise from somewhere other than the originating enterprise.

A: XDS On-demand viewers tend not to offer “source” actor capabilities i.e. they cannot publish a document to the XDS domain. As such, these viewers do not let you make changes to the documents. This may change over time!

Part 2: Answers to XDS/XDS-I webinar audience questions

Dr. Bak's responses, continued. 

6.) Q: Do you view the point to point nature of DICOM (e.g. AET and ip address requirement) as a detriment to XDS-I? i.e., consumers of images need to have a DICOM connection to PACS and have a configured AET...

A: Absolutely! We are now moving to a WAN world with any number of users who can be anywhere…the vision of “anytime, anywhere, anyplace”! If we rely on DICOM to retrieve, you have to configure systems to talk to every possible other system, setup static IP addressing at the server and client end, etc.…totally impractical!

It is better to relegate DICOM to the LAN and shift to Internet protocols for all WAN traffic.

7.) Q: Are any conventional PACS archives currently XDSI compliant or does XDSI require the creation of a vendor neutral archive that is XDSI compliant.

A: XDS does not require the use of a vendor neutral archive. The PACS vendors offer XDS-I compliance (not all but they are all moving to this), specifically: 1. Source actor compliance – this allows the PACS to publish its data to the XDS domain 2. Repository actor compliance – this allows the PACS to host the images as well as the documents that are published. This is a good thing as it allows the hospital to maintain custodianship of the images as well as the published “documents.”

8.) Q: Interested in finding out name of Proxy server vendor used - capable of JIT order messages.

A: Please look at Mawell, DeJarnette, Softmedical – there are a few more but I am not overly familiar with all of them!

9.) Q: What patient & exam identifiers are used to query the Registry?

A: The primary query key is the global patient ID. Additional information includes patient demographics, etc. but not much of this is very reliable. Having said this, for imaging information, the Registry holds Modality, Body Part, procedure Description, Institution Name, Exam Date. All of these are queriable fields.

10.) Q: How do second opinions, consultations, over reads, preliminary reports associated with a given study get handled (i.e., created, transmitted, stored)

A: XDS-I provides a mechanism for changing documents. One can add addendums, delete documents and deprecate a document. The IHE XDS-I Content Supplement document describes a varity of use case that XDS-I shod and can support. One of these is called the “Treatment Consult” use case. This is an example of:

-Publishing a study

-Asking a specialist or radiologist to provide a consult

-Adding a final report or consult report to the study “record”

Part 1: Answers to XDS/XDS-I webinar audience questions

Dr. Bak's responses to audience questions are going to be added here as series of posts over the next day. Feel free to ask additional questions or add your opinion in the comments section below.

1.) Q: Are there free standing/independent imaging centers in Ontario? How do  - Dan Banach, OAMRI, RIS/PACS Admin

A: Ontario has many independent clinics. The Ontario Ministry (eHealth Ontario) is looking at a business and technical model to integrate these clinics in to the existing infrastructures deploy and operating. The details of this are not public knowledge as of yet!

2.) Q: How do you communicate Usernames and passwords across multiple systems or do you require user to log into each system independently?

A: IHE offers a profile called XUA that details how to federate usernames and passwords. In practice this is essentially a federation of Active Directories…which falls outside of XDS-I and/or PACS. This is an IT task that is challenged more by governance than technology.

3.) Q: How is security handled e.g. how is ad hoc access to images in a hospital PACS facilitated (assuming said PACS is behind a firewall, etc)?

A: In any DICOM network one has challenges. If the image retrieval is via DICOM, you really have to deploy a VPN and open up the firewall to let DICOM traffic into the LAN. This is not desirable and usually addressed by putting the PACS in a dedicated hospital LAN..Even then IT gets nervous!

The alternate is to put a WADO server in a DMZ. External XDS consumers hit the WADO server over the WAN. The WADO server connects to the PACS on a separate LAN.

My experience so far is that all hospitals expect traffic to travel over a VPN. If combined with WADO, this provides an acceptable level of security.

My personal opinion is that we should develop capabilities that relegate DICOM to the LAN and leverage internet protocols for all transactions over the WAN. If done correctly, traffic can flow over both private and public networks. Such capabilities could augment XDS-I.

4.) Q: What is the cost to the outside hospital to place images in the repository to the tertiary hospital, if any?

A: Tough to answer! It all depends on what is in place and what extra you have to procure for the local site and for the XDS domain.

5.) Q: Not many facilities in the US enforce a Key Image policy for their reading radiologists. In light of that, do you advocate publishing a KOS containing every image in the study?

A: It all depends on the user case. For most of the use cases, you do want to publish the entire study. However, I would say that the pressure is now on to put key image notes in place as XDS offers up the opportunity to share to a much broader audience of consumers…who do not always want to wade through a full study. Pressure to offer better service will drive the shift to produce key image notes

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XDS Webinar on Feb. 23

The next ImageSharingForum.com webinar has just been confirmed for Tuesday, February 23, 2pm ET. The session will focus on XDS, and our featured presenter will be Peter Bak, the former Director of Architecture, Medical Imaging, at Canada Health Infoway. Peter's full bio his available here. If you haven't already registered for the webinar, you can do so here.

Forum readers - are there specific areas you would you like this webinar to focus on? Post your ideas in the comments field so that we can incorporate them into the session material. 

 

Today's featured speakers

Hamid and Dr. Dreyer at "mission control".

Why is your site thinking about image sharing?

Why are you interested in image sharing? Please comment here so that we can break the forum out into relevant areas of interest.

What did you think of our first webinar?

Please comment with feedback and suggestions for next time.

-Jackie

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Next webinar - Feb 23?

We are targeting Tue Feb 23 for the next ImageSharingForum.com webinar. It will focus more on the standards that will come into play when sharing images, specifically XDS (so, be sure to invite your CIO). Please comment with feedback and availability. We want to make sure the content is useful to all.