Month: December 2009

Essential Ingredients of a PACS-Neutral Archive

Whether its name is PACS-Neutral or Vendor-Neutral, the Enterprise Archive whose major feature is data exchange between disparate PACS is sometimes hard to identify.  The situation is similar to the Christmas shopper trying to differentiate the real designer handbag or watch from the fakes.  Simply publishing a list of the “real” Neutral Archives is not sufficient, because products change, and entry to the list could be as easy as making a few key changes.  A better way to identify the real Neutral Archive is to use a carefully conceived check list.

I came across just such a check list at this year’s RSNA.  It was a piece of booth literature created by Acuo Technologies.  While I completely agree with a good deal of the Acuo list, I have made some additions and changes to make it my own (and the elements from the Acuo list are reprinted here with their permission).  I offer the following check list to those that are interested in understanding what constitutes a fully functional Neutral Archive.

Bi-Directional Dynamic DICOM Tag Morphing – On-the-fly conversion/mapping of data elements in a DICOM header to facilitate data exchange between disparate PACS.

DICOM – Full conformance with latest DICOM SOP Classes (SCU and SCP) with no exceptions.

Non-DICOM – Methodology for accepting and managing non-DICOM data objects, most notably J-PEG and PDF objects, preferably via Web Services and optional support of WADO for viewing .

ILM Methodology – Intelligent Information Lifecycle Management (ILM) – data movements internal and external to the system based on meta data associated with the study data (study date, study type, patient age, etc.) Separate ILM strategy for each organizational node (facility, department) .  Automated, user-defined Data Purge mechanism with manual supervision. Node-specific Retention Flags that would over-ride a Purge operation.

Unique ID – Ability to make the ID associated with incoming data  unique (throughout multi-facility enterprise) without need for Master Patient Index (MPI).  Internal Pseudo-MPI capabilities tie individual facility MRNs to the same patient (in a multi-facility organization).

Pre-fetching / Auto-routing – HL-7 or DMWL enabled Pre-fetching of relevant prior data being managed by the Neutral Archive and Auto-routing of that data to the appropriate department PACS either directly or through the Archive’s local Facility Cache.

Flexible Architecture – Server and storage Hardware Agnostic, Primary and Secondary Mirrored Subsystems,  Active-Active or Active-Passive modes  with Automated Failover and Automated Reconciliation between the two subsystems.

Data Integrity –  Synchronized updating of meta-data (patient/study level changes). The Neutral Archive will propagate updates received from RIS(s) or via manual update to all destinations that received studies in order for all available patient information to stay in sync.

Storage Reclamation – Ability to reclaim storage space following media migration or data purge.

Data Compression – Preferred compression syntax is JPEG 2000 Lossless but capable of negotiating any DICOM supported compression syntax.  No proprietary compression syntax.

XDS-I Manifest – Automated creation of XDS-I manifest for all data objects ingested by the Neutral Archive, with Optional XDS-I Registry and Repository available when needed.

Transaction Logging – HIPAA compliant Logging and Reporting by Organizational Node

Experience – Neutral Archive vendor has years of experience in the business: Millions of studies migrated between all of the major PACS, a dozen or more instances of the Neutral Archive deployed

The reader will notice that I did not include on the list one of my favorite items: the UniViewer.  While a unified multi-modality viewing application is a highly desirable option, and the key to image-enabling the EMR, I don’t think the viewing application itself needs to be an integrated component of the Neutral Archive.  That’s because it can easily be a free-standing add-on.  There are a number of zero-client, server-side rendering display applications that run on their own server platforms and simply access the image data being managed by the Neutral Archive.  There seems to be no advantage to forcing the Neutral Archive vendor to pick one at the expense of the others.  It seems totally appropriate to let the Health System make this selection, knowing that there are no complicating interface issues.

A final comment…The above list is by no means a complete description of, or specification of, a PACS-Neutral Archive.  Gray Consulting has created a very comprehensive Request For Proposal document that accurately defines a Neutral Archive.  The Technical section of this RFP contains 22 categories of questions that span 120 pages.  Anyone interested in a thorough investigation of this subject is welcome to contact Gray Consulting.

Is it a PACS-Neutral Archive or Vendor-Neutral Archive?

I guess that depends on how far back in time one extends the search.  I began writing about a PACS-Neutral Archive back in 2007, and those posts are still available on this web site.  I chose the term PACS-Neutral, because I believed that it best described the focus of the neutrality.  The archive would be neutral with respect to the individual PACS systems that would inter-operate with it.  A key to the Neutral Archive’s ability to exchange data between disparate PACS is the feature now commonly referred to as bi-directional dynamic tag morphing.  In this sense the term PACS-Neutral did not refer to the absence of any vendor preference or vendor logo, it referred to the ability of the archive to effectively exchange data between PACS (systems) from different vendors.

As time moved along, the term Vendor-Neutral Archive emerged.  I am not certain of the initial source or sources of this term, or of the logic behind its creation.  Perhaps it came to be simply because the term PACS-Neutral Archive was already in the literature.  (Branding is such a personal thing to some organizations and individuals.)

I have been told that the term Vendor-Neutral Archive refers to an Archive that is neutral with respect to Vendors.  Presumably that means PACS vendors and Server vendors and Storage Solution vendors, because there is clearly a neutral archive application vendor with a vested interest in the system.

I can almost see and hear Andy Rooney of 60 minutes explaining to us “PACS-Neutral, Vendor-Neutral, it’s the same thing, and why people have to invent multiple names for the same thing is beyond me.”.

So just to go on record, as far as I’m concerned, the two terms are interchangeable, and hopefully none of the vendors (both those with the technology and those without) will mount a sinister campaign claiming that one name refers to a technology that is either superior or more feature-rich than the other.  We’re just getting something going here, so let’s make an effort not to confuse everybody.

Besides, months from now, I suspect we will all be simply using “Neutral Archive”, and we will all know what we mean.  At least that is my fervent hope.

RSNA 2009 Meeting signals beginning of a Paradigm Shift in Medical Image Data Management

Based on my conversations with both the vendors that really have  PACS-Neutral (Vendor-Neutral) Archive technology and those that do not, a significant number of attendees of this year’s RSNA meeting in Chicago (Nov 29 thru Dec 4), were seeking information on the subject.  Numerous motivations were sited for the surge in interest including: time and costs associated with data migrations, difficulty exchanging data between disparate PACS, and the requirement to image-enable an Electronic Medical Record system.  Having written extensively on the subject of  Neutral Archives, I find it encouraging that a growing number of Health Systems large and small are finally “getting it”.

My perception of the overall “buzz” on the subject at this year’s RSNA reminds me of 1992, as seventeen years ago the radiology PACS market had come of age and the degree of misinformation and deliberate obfuscation on that subject during that RSNA was shameful.   As Yogi Berra has said, “It’s deja  vu all over again”.  Numerous vendors that actually do not have Neutral Archive technology were actually claiming at this year’s RSNA that their Radiology PACS could effectively function as a neutral Archive.

Now that the vendors (both the haves and the have nots) are preparing their marketing strategies for Neutral Archive, the industry consultants are also coming out of the woodwork, preparing their statements of work.  It’s a good thing there are some good articles on the subject, so the consultants don’t have to learn the material the hard way.

So I guess if the vendors and the consultants are all over it, the age of the Neutral Archive has arrived.

Accurately defining what constitutes the Neutral Archive should be the next order of business for any Health System with serious interest, and especially for those organizations that have any of a number of problems whose solutions require this technology.  While there are at least ten key feature/functions included in that list, the one most important would be the ability to execute bidirectional dynamic tag morphing.

A good deal of information on this key feature/function has already been written and posted on this web site and on the new web site hosted by DeJarnette Research and I suspect a good deal more will be forthcoming in the next few months.  This time, if we are going to avoid a good number of the missteps and detours experienced in the early years of radiology PACS deployment, we need to make sure that detailed and accurate information on the subject is readily available to the decision makers.  My advice to the interested Health System is simply this, pay attention to the source of information on this important subject and always confirm the information with multiple trusted sources.

And now a word from our sponsor:  Gray Consulting has developed a simple but effective 3-Step Action Plan that will assist a Health System in understanding the subject of Neutral Archives, determine the compatibility of existing PACS with such an archive, and determine the costs of future data migrations that could be avoided.  Contact Gray Consulting for a description of the 3-Step Action Plan and a quote.