Month: February 2008

Cost-effective Business Continuity Solutions – So much more than Data Back-up

Most Radiology PACS currently in use have some sort of data back-up in place. At the very least, the Directory database and the Data database are backed up daily to digital tape. In my opinion, digital tape is not reliable and the problem is you don’t know what data you have lost until you try and retrieve it. My low opinion of digital tape is supported by a number of reports from the field. I suspect the vendors that continue to insert digital tape back-up solutions in their early round quotes, do so in order to keep the price of the system down, but a much better solution is worth a few dollars more.

The “tape-less” back-up is a much better back-up solution. Instead of digital tape on a shelf or in a mechanical jukebox, a far more reliable and performance-oriented solution is to store the back-up copy of the Directory and the Data on spinning disk. Thanks to today’s pricing, a multi-processor, multi-core server coupled with a disk-based storage solution is only slightly more expensive than a digital tape library. I think the reliability is worth the additional investment.

Why stop there?

Instead of just writing a copy of the Directory on the back-up storage solution, why not install a second instance of the Directory application (Oracle, Sybase, DB2, SQL, etc.) on the back-up server? Now you have a reasonably cost-effective Disaster Recovery solution, depending on where you have physically placed that back-up system.

Why stop there?

Why not add a second instance of the PACS application to the back-up server? Now you have a reasonably cost-effective Business Continuity solution. Of course this complicates the PACS application considerably. The optimal software configuration would have the two Servers (Primary and Secondary) functioning in an “Active-Active”mode, and that would mean that the Directories are being automatically synchronized in near-real-time, and the study data is being copied from Primary to Secondary on a fairly regular basis.

Only the newest generation of PACS can support this configuration. Most of the PACS being sold today can support a “tape-less” back-up server, but they do not support a second instance of the Directory application on that back-up server. The few that do support a second Directory do not support a second instance of the PACS application. Fewer still that support a second instance of the Directory and the PACS application have the back-up system operating in a standby mode. The Back-up takes over only when the Primary is off-line for scheduled or unscheduled maintenance. While this version of back-up may not sound so bad, the fact is that the failover and eventual reconstitution processes are often manual and labor intensive.

The point in all of this is, with today’s cost of hardware it doesn’t make sense to settle for a back-up solution with questionable reliability, when a much more reliable Business Continuity solution is affordable. The problem is most PACS currently being sold are “old” generations of system architecture wrapped in pretty GUI and flashy 3D applications. While GUI and display applications are important, I believe that the system architecture that supports a solid Business Continuity solution is more important, and sooner or later those old generation PACS are going to be upgraded. You can tell a lot about the longevity of a PACS, by investigating the various back-up solutions that it can support. Why start a five year contract with an old PACS? Do you have room for a forklift in your data center?

The Problem with Proprietary Data/Object Formats – their Impact long after Data Migration

This is another take on a long-standing problem with most of today’s Radiology PACS: proprietary Data/Object Formats. It has been at least four years since Presentation States and Key Image Notes were included in the DICOM standard, yet the majority of PACS vendors continue to treat these key work products as proprietary objects. The most consistent excuse is “There are many more features on our engineering schedule considered to be more important to our users.”

I can almost believe that story, since I have found that most users are not aware of the implications of proprietary data objects. Since almost every PACS supports the creation and display of Presentation States and Key Image Notes, the fact that most PACS treat these as proprietary objects is lost on most buyers and eventual users. Provided that these objects are kept within a given PACS, there is no apparent negative to their being proprietary. The user may not experience a situation where the proprietary nature of these objects presents a problem.

The problem arises when the user of one of these proprietary PACS tries to forward study data to another Facility or Health System that is using a different PACS. Whether that other PACS is DICOM conformant or not, unless it is the same PACS, those presentation States and Key Image Notes cannot be transferred, accessed, or displayed. Physicians using the other PACS will not have the benefit of seeing exactly what the radiologist interpreting the study saw in the images or what he may have typed as a text message. The benefit of these “work products” is lost.

The problem also arises when a user of one of these proprietary PACS tries to copy study data to a CD/DVD. The proprietary work products either cannot be copied, or they cannot be accessed and displayed by another PACS. This is one of the reasons why there is so much consternation over the current CD/DVD copying solutions on the market. The vendors of these proprietary PACS typically have to place a copy of their own viewing software on these CD/DVDs, because their proprietary viewer is the only way to view their proprietary study data.

The real problem will manifest itself only after the user has decided to replace the proprietary PACS with the next PACS. Data migration services will typically migrate the study pixel data to the next PACS, but few of these services currently migrate any proprietary study-related data objects. To do so would require knowing where these objects were stored in the PACS, how to extract them and how to convert them to their DICOM counterparts. This extraction, conversion, migration is not being performed and as a result, those proprietary data objects are lost forever. The images are available for historical comparison in the next PACS, but none of the proprietary work products are available. Now imagine the implication of having to window and level all of these priors again, when they are recalled for viewing with the new images. Imagine not having the spine labels, and not having any other annotation or overlay graphics created when the prior was first interpreted. That’s working without benefit of prior information, or a possible expenditure of time redoing all that work.

A PACS should treat Presentation States, Key Image Notes, .wav files, Technologist Notes, Scanned Documents, even the Radiology Report as DICOM Objects, not only so they can be shared with other systems today, but also so they can easily be migrated and used in the next PACS. DICOM-conformance is always in the user’s best interest.

Now if a prospective buyer knew the negatives associated with proprietary data objects, would they choose a proprietary PACS anyway? Logic suggests that they should think twice. At the very least, if an organization goes ahead with the purchase of a PACS that still creates any proprietary data/object formats, that organization should negotiate a “no-cost” data migration clause in their contract that pins the cost of moving these proprietary objects to the next PACS on the vendor who has continued to choose NOT to conform to the standard.

Lack of DICOM conformance is a type of vendor lock. I believe that the PACS vendors still believe that anything that complicates moving to another vendor’s PACS may persuade the organization to stay with the incumbent. It’s time to make them pay for that strategy.

Coming Up For Air

Here it is February. Where did January go? For that matter, where did December go? My bad! I’ve been so negligent with keeping my site up to date. It’s not that I was chasing snow or anything. I’ve been very busy with a number of projects; two separate RFPs for Radiology PACS, a Project Plan for a large multi-site health system, and a PACS-neutral Archive project.

I really did want to publish a commentary or two on my RSNA ’07 observations. There certainly was plenty of inspirational Material.

  • GE finally has a decent Radiology PACS (through acquisition). Now what?
  • A number of vendors start talking about PACS-neutral archives, but you really have to look hard for the vendors, and then look even harder for anyone who can speak to the subject.
  • It’s truly amazing how few vendors consider themselves DICOM-conformant, yet they do not support DICOM Presentation States.
  • Apparently 3 MP color display panels are now the norm in Diagnostic display stations.

Let’s just say I have some new things to say about some old subjects, and a few things to say about some new subjects. Sorry for the tease, but I need a little time to collect my thoughts. Check back in a few days and you’ll find some posts on such subjects as:

  • The problem with proprietary data/object formats, their impact long after data migration
  • The beauty of media-neutral storage solutions
  • Cost-effective Business Continuity Solutions, so much more than data back-up
  • Double-check that quote configuration, because there are lots of hidden costs that sneak into the picture at contract time.