Friday, December 5, 2014

XDS Implementation Issues part 3

The previous two parts discussed how XDS fits into the IHE technical framework and also its relationship with other ITI profiles that are needed to provide the infrastructure to make XDS work.
Showing the 5 XDS actors
In this part we’ll talk about the document exchange profiles, i.e. XDS itself and its “variations” including XDR, XDM, XCA, XCPD and their imaging implementations.

The Cross Enterprise Document Sharing (XDS) profile facilitates the registration, distribution and access across healthcare enterprises of patient electronic health records. It is a standards based specification for sharing documents between healthcare enterprises. These documents could be a “view” into an electronic record, for example, specifying a certain episode of care or a summary. At a minimum, a consumer or receiver could add the received document (e.g. a pdf) to the patient record, but because of the electronic nature of the exchange, it is expected that the recipient would update its own electronic record (i.e. database records) with the relevant information from the document so it can be viewed and interpreted using the EMR user interface.

As explained in the earlier part, XDS has multiple actors, i.e. in addition to the document source/repository (which could be an enterprise archive such as a Vendor Neural Archive or VNA) and the document consumer, it relies on a document registry for the registration of the documents and to allow potential consumers to query them. A Health Information Exchange typically provides this registry, which can be public or private.  The requirement for this HIE infrastructure is one of the implementation issues, i.e. what if we don’t have a HIE in place (yet)? Another problematic scenario is when the source is outside of the consumer domain, for example if it is not covered by the HIE reach. That is where the other “XDS variations” such as XDR and XCA come into play.

With regard to information sharing, one can recognize three different models, each with a specific workflow and corresponding XDS-like profile:
  1. Centralized discovery and retrieval, where a community uses a common infrastructure to push and query/retrieve content. This is where we use the XDS and its imaging counterpart XDS-I. A typical use case for this profile would be publishing patient summaries upon discharge from a hospital and allowing physicians to query and retrieve these. Other examples are referrals from primary physicians to specialists with the relevant information, sharing radiology reports and images from imaging centers, communicating lab results with ordering physicians, and relaying prescription information between physicians and pharmacies.
  2. Direct push, where the information is sent directly to a recipient, i.e. point-to-point. A registry is not used, and the profile to use is the Cross-Enterprise Reliable Interchange, aka XDR and XDR-I. Another option is to send a secure email, or simply use the “sneakernet” by copying the information onto a CD or flash drive and let the patient deliver it to the physician. These profiles are called XDM or Cross Enterprise Document Media Interchange. The use cases for these profiles are similar as for the centralized discovery and retrieval, for example, referral information from a physician to a specialist, or summary information from a hospital to a long-term care facility, with the difference that the information is directly sent to the recipient. This is typically only done between “trusted” partners who have a strong relationship, and established policies and procedures for information sharing using a secure semi-permanent infrastructure.
  3.  The federated discovery and retrieval, which is used when the consumer and creator are not within the same domain and the information spans multiple communities. This is called the Cross Community Access (XCA and XCA-I) to documents and images. The consumer needs to know in which community the patient information is available. In case the particular community is unknown, one can use the XCPD or Cross Community Patient Discovery mechanism to find out. Typical use cases are when patients live in multiple residences, seek care in another community, move, or go on vacation.

As mentioned earlier, one of the issues with early XDS implementations is the lack of infrastructure, i.e. having either a public or private HIE available that can be used to register the information and provide query capability. Having the XDR and XDM option available should not deter a closer integration, similarly to being in another community, as we can use XCA and XCPD in those cases. Note that all of the XDS family profiles share the same transactions, therefore, to support either one or all of them should not be too big of a burden from a vendor implementation perspective. The same applies for the user community, i.e. there is no reason to NOT use any of these standard profiles instead of the many proprietary solutions that are currently used for information exchange and do little more than lock you into a single service provider. However, there are still some lingering issues with the metadata used to identify the objects (i.e. documents and images) that are exchanged, more about that in part 4 of these series.

My RSNA 2014 Top Ten

View from McCormick place to the city
I have a love-hate relationship with the annual RSNA radiology tradeshow. I don’t really care about
the long lines to wait for the shuttle bus and Starbucks, the expensive food, and of course the cold weather outside, even though it was relatively warm this year. And of course the walking, as my Fitbit® logged 7.5 miles on average going from one end to the other end of the exhibit halls. But the good things definitely make up for the bad parts, i.e. the networking with others in the industry, catching up with who is where and doing what, and last but not least, seeing what’s new from the vendor exhibits.

View at the exhibit hall
There were no spectacular new developments this year, rather more a continuation of and, in some cases, merely a slight improvement in functionality and features. Especially in the imaging IT space, the lack of significant progress has been frustrating for users who complain about workflow issues and lack of integration. Every manufacturer talks about a Vendor Neutral Archive or VNA, which is supposed to serve many specialties and an EMR, which is supposed to provide a patient-centric approach towards information presentation with a “simple” universal viewer plug-in, but in talking with users, reality is different.

An example of the criticality of proper workflow support was shown in the recent Ebola case in Dallas, where supposedly the information that the admitted patient, Thomas Duncan, had just arrived from West Africa was not communicated between the admitting nurse and the treating ER physician, resulting in the discharge and fatal result as has been widely publicized. The hospital admitted that they made significant changes in the EMR configuration (which is EPIC) to prevent this from happening again.

But let’s talk about what’s new, or noticeable, at least in my opinion that was shown on the exhibit floor:

1.       We need Vendor Neutral Video (VNV) in addition to a VNA – Many users are considering a
Multiple video sources combined
VNA, however, there are still many disparate systems without digital connections that only can be integrated by combining their video signals, which could be coined as a VNV solution. This is especially important for the OR, which has several measurements to be recorded, such as EKG’s in addition to live video feeds and DICOM image displays that all need to be available for a surgeon.

Demostrating Google glasses using a
DICOM viewer

2.       Google glass for DICOM image display – Over the past few years, vendors have shown
gesture-driven user interfaces based on commercial gaming console detectors, this year, a couple of researchers showed not only hand but also “finger” based interfaces, and the ultimate interface using Google glasses. Talking with radiologists, many suffer from wrist and arm injuries caused by the daily repetitive mouse and/or trackball movements required to go through image sets. The alternatives are not quite ready for prime time yet, but it is clear that we need a better alternative; otherwise, in another 5 or 10 years, a major part of the radiologist community is going to be on disability leave.

3.       Monitor size and resolution is ever increasing – Extra-large size monitors (70, 84, or even 110

inches across as shown by Beacon) are useful when the user is relatively far away such as in the
12 MPixel display (note icons on bottom)
OR, but also in a conference room setting. With regard to resolution, Barco showed that last year’s 10 Megapixel is this year’s 12 Megapixel, with a different aspect ratio, optimal for displaying larger size icons, which allows for easy scrolling. An interesting application for color in mammography was to label the prior image in a different color, (e.g. yellow) vs the current study (e.g. blue), which reduces the chance of mixing up the new and old images. By implementing its own driver, Barco also showed how to create a “loupe,” which does not magnify but increases the luminance considerably, simulating a “hot light” as used for film.

4.       Cone beam CT is expanding beyond dentistry –  Cone beam CT scanners are already widely
Ever larger cores for the cone beams
used for dentistry applications, especially where high resolution is needed to simulate implants. There is a growing application field for ENT where, especially for the inner ear, high resolution is preferable. Now with ever-increasing bore sizes, it also can be a less expensive alternative for extremity imaging compared with traditional multi-slice CT scanners as shown by Claris.

5.       Breast ultrasound imaging becomes multiplanar ­– Ultrasound images are typically 2-D, or, if
Scaning a breast phantom using a
commmercial Ultrasound wth a fixed
acquired as a loop, have a time component. Because of the hand-held operation, registration of these images with each other is very hard if not impossible. What if the images are acquired using a registration device that controls exactly the direction and relative distance from each other? The result are a set of images that can be used to do a multiplanar reconstruction or even a 3-D, similar to what is done in CT or MRI. The registration device as shown by Sono Cine looks conspicuously like the first-ever ultrasound unit. Regardless, this brings a completely new dimension to ultrasound, especially for breast imaging, this could be a great advantage.

Entry cautions

6.       Safety is critical – The solutions shown at RSNA range from sophisticated high-tech imaging solutions to simple devices that can have a major impact on patient and personnel safety. An example of such a pragmatic device is access control to MRI rooms as shown by Aegis. Incidents whereby people got hurt because of flying metal objects such as chairs, big oxygen cylinders and others that are attracted to the strong magnetic field are not uncommon. Proper protection could make a major improvement and satisfies the increasing scrutiny by Joint Commission inspections.

Definitely not caustrophobic
7.       Niche MRI’s are becoming available – Standing-up MRI’s have been valuable for awhile as   down or when standing up, especially when it includes the spine. A logical evolution is the sitting down MRI as provided by ParaMed, as many people spend their days sitting in a chair, and again, lying down on your back in a regular MRI might not show the cause of the back pain as a sitting down image would.

8.       True multi-modality multi-plane system – The illustration shows a
Seems kind of crowded
person that is scanned using four flexible arms, with two X-ray source and detectors using ABB robotic arm technology, called 4DDI. It is similar to a bi-plane system but with the difference that the rotation and angulation variations and combinations are virtually unlimited. It can function as a digital X-ray unit, a cone beam CT, fluoroscopy unit, all in one. This particular device was semi-experimental, apparently there has not been a single install yet, and I could not quite figure out from the sales people what the application might be for this device. So, it will be interesting to see if it makes it to next year’s RSNA.

9.        DR in a box – For veterinary and other mobile applications, such as a nursing home, the
Container with digital, wireless
plate adnd computer
Carestream DR in a box is a good solution. The plate is a wireless DR plate, with a PC used for QA and preliminary viewing. The battery life of the plates are sufficient for more than 100 exposures, which should be OK for human use; for veterinary use, it might barely cover all the views needed to image the joints for only 2 horses. In the latter case, one would require extra batteries for the plates to be available.

A true table top
10.   Tabletop CR finally arrived – Carestream introduced a follow up of their VITA CR system, which has a smaller footprint and weighs only 26 lbs. The unit’s serviceability has greatly improved as almost all of the moving parts that cause the most problems are integrated into a cartridge, which is very easy to exchange. In the case that an error occurs, the user takes out the cartridge, replaces it with an on-site spare, and the broken one is refurbished at the manufacturer to be re-used. It is even simpler than replacing a cartridge in a printer. A test plate is included with the unit which shows whether it is still in calibration. This is a great solution for small clinics and for emerging and developing countries where high serviceability is a key.

This year celebrated 100 years of RSNA. This event has grown tremendously, and even though
Having the honor to finally meeting
Dr. Wilhelm Roentgen in person
attendance and booth size has been decreasing over the past few years, it seems to have stabilized. Gone are the days where vendors would splurge, instead, cost cutting is everywhere, not only on the user but also on the vendor side, but RSNA still draws more than 50,000 attendees from around the world. I personally still enjoy it, as most attendees do. One of my friends and colleagues likes to call it a “workshop,” i.e. he does the work during the event and he takes his wife who does Christmas shopping. Not a bad idea, try it, I am sure your spouse and/or partner will like it.