Monday, February 20, 2012

PACS 2.0 through IHE workflow implementations.

View from the deck of the MedWEB training facility

OTech delivered its first week of IHE training high in the Sierra Nevada Mountains, minutes from Lake Tahoe and major ski resorts, in the brand-new MedWeb training facility during the first week of February. Why is proper IHE implementation so critical? Based on my observations, feedback from our students, and polls from our newsletter, I estimate that the majority of the current PACS implementations in the US run at half-speed. They are based on 20th century connectivity technology and have not made the jump to implement the many IHE profiles that have become available since the early 21st century. They implement HL7 standards to exchange orders that result in a DICOM worklist, use DICOM to exchange images and allow modalities and third party workstations to query and retrieve the PACS archive. This is where it stops. They might have an API interface to allow a HIS or EMR to launch a window for image viewing, but require the use of their own, proprietary viewer.
Just implementing the IHE scheduled workflow profile alone could result in a significant improvement in efficiency, major reductions in potentially lost images or studies, and reduced turn-around times for procedures. Let’s look at the MPPS or Modality Performed Procedure Step. While most modality vendors have long ago implemented this DICOM service, there are still major PACS and RIS vendors that have not yet implemented MPPS.
The MPPS is an automatically issued transaction from the modality that signals when a procedure has started, completed or canceled, indicates the number of images and other objects such as presentation states or measurements that are generated, and it provides any order changes and updates to both the PACS and RIS.  When properly implemented, the modality worklist is automatically updated as soon as the study is started, and the finished procedure is immediately added to the radiologist workstation worklist and changes in the procedure are automatically updated in the RIS. Without MPPS, a technologist might have to complete or “verify” the study at the PACS and RIS, and there is a chance that a radiologist could start reporting on an incomplete procedure or wait unnecessarily to begin reporting.
Another major component of the scheduled workflow profile is the so-called STC or Storage Commitment, which is the hand-shake between a modality and short-term archive. It can also be used as a handshake between a short- and long-term archive, which can be hosted on-site or in a cloud. As more and more systems deploy enterprise archiving solutions and off-site storage, this is a critical transaction.
The best known IHE profile is the PDI or Portable Data for Imaging, which specifies how to store images on a CD so that they can be read by another institution and imported into their PACS. Unfortunately, there are still institutions that create proprietary CD’s, which cause unwarranted charges that “DICOM does not work,” when the real culprits are institutions and PACS vendors that simply do not follow the rules.
These are just two of the most popular profiles, there are many more that can have an impact on daily workflow, or emerge when an archive is migrated to a new version or vendor, and suddenly all of the image overlays have disappeared or when deleted images suddenly re-appear.
Why is it that these IHE services are so under-utilized and poorly implemented?  First of all, there are still PACS vendors who are lagging with the implementation of these profiles. Second, there is a still a major lack of knowledge among the user community about the “hidden” capabilities in their systems. When talking with the service engineers that install modalities, I find that they often do not install the advanced features because the user does not request them, or it is too much work to get a service representative for the PACS system to come out to configure, test and verify that it is working, or it is improperly configured. As one PACS administrator told me, “It was not worth the hassle therefore I turned it off”.

View at lake Donner,  a couple of
 miles from the training facility

With regard to training, MedWeb has taken the initiative and started to offer training on the subject of IHE in partnership with OTech in their brand new facility in the High Sierra Nevada. In this state-of-the-art training center, students can enjoy the environment, and, if they wish, even get in a ski run or two in the early morning prior to the class.

if you are interested in scheduling intensive hands-on training loaded with practical exercises using the in-house computer lab and virtual PACS environment, contact OTech at  With more people trained in proper IHE implementation, we will achieve a better understanding of the IHE advantages and a more widespread implementation that will result in proper implementation and higher efficiency.