WARNING: Our Scanner May Not Work With Your PACS…or should that be "Our PACS May Not Work With Your Scanner?

On the heels of the prior private tag post comes some further information from GE, which provides paranoiacs like me more to worry about.

This is a known issue with the AGFA system in which the AGFA PACS does not support WW/WL > 13 bits. Per the DICOM standard the ww/wl values can as large as the image data. Per the HDMR2 DICOM and Annotation SRS (DOC0084074 rev 5) section 2.1.2 Smallest Image Pixel Value,Largest Image Pixel Value, MR image data is stored as 16 bits.

It seems that Agfa is only supporting 16 bit for a small number of modalities. The Impax developers are working on a solution to this problem. They are trying to work the fix into the next service pack or perhaps the next service update. I recommend that the you contact their AGFA representative regarding this issue. . .

Ummmm… Guys, this is a real problem, and I think both vendors really should have disclosed it. Unless perhaps this bit problem is more widespread than we know. I would like to know if any PACS out there can deal with 16-bit output from a scanner without modification. If so, please let me know which product can do so. If not, someone please tell me why the scanners’ main output is in a form that the majority of the PACS systems cannot handle. And if Centricity (and IntegradWeb for that matter) can’t deal with the 16-bit output, then this makes no sense at all.

Add as an aside the fact that every Barco monitor I’ve ever seen attached to a PACS system runs at 8 bits, or at least that’s what the Windows Display Properties control says on these machines.

Frankly, I’m confused. And very, very concerned about what we are seeing or not seeing. I am disappointed in both vendors for not making this situation clear. While I think my group of radiologists is top notch, I find it difficult to believe that we are the first to have discovered the discrepancy.

So, who is at fault here? Is it Agfa for not being able to receive the full output from the GE MRI, or GE for sending data that the PACS cannot completely digest? Let’s be democratic and blame both of them. And both need to work on the solution. Which I’m assured is in progress.

A Private Little (Tag) War

“Mugato” from the Star Trek Second Season episode, “A Private Little War”
Courtesy Paramount Pictures/CBS Television

OK, only PACS aficionados who are also Trekkies will get the reference, but I thought it was attention-grabbing.

We have recently upgraded our GE MRI, adding various bells, whistles, coils, software, and various and assundry other items. I myself have been scanned in this machine, and I can tell you that the new, improved version is louder than a freight train as heard from the track’s perspective. However, the images are excellent. Well, I should say that the images as viewed on the MRI console are excellent, but once they make it to our Agfa PACS, they would rate as only “good”. It seems there is much degredation in the display, and we have been asking about this for quite a while.

The fault appears to lie with DICOM, the communications protocol of digital imaging. Well, that’s actually a mis-statement, as the real fault lies with the vendors and their use or misuse of the DICOM standard. In this case, the culprit is probably GE, although they aren’t the only bad actors in this venue. I have also noted severe problems with Fuji CR in the past not displaying properly on an Amicas PACS. In both cases, the modality makers tried their best to indict the PACS for the situation. However, while the PACS does bear some responsibility, the lion’s share of the blame probably goes back to the modality.

Now, you don’t want a complete course in DICOM, and even if you did, I couldn’t begin to do it justice. If you are truly interested, please consult David Clunie’s website, http://www.dclunie.com/, for the most complete information possible. (God Himself consults David when He has a DICOM question.) For the purpose of this discussion, you need to know that a study, a group of images and associated data, is called an object, and it has a header, which is some alphanumerical data tacked onto it. Michael Gray, of Gray Consulting posted this link as an example of what the header looks like. The header contains “tags” which in turn have code for “attributes” And this is where the trouble starts. The even-numbered tags are Public, representing standard variables for PACS systems, archives, and modalities. Ah, but the odd numbered tags are Private, and therein lies the trouble.

There was a huge discussion on AuntMinnie.com, prompted by my article, “The Dalai’s Laws of PACS” a few months ago, where many of the Great Ones of PACS, including David Clunie himself, Michael Gray, and of course Mike Cannavo, the One and Only PACSMan, as well as the phenomenal Digital Doctor, and several very, VERY wise folks hashed out the vagarities of vendor-neutral archives. The modalities were not really mentioned much, but as our experience reflects, they have this problem too.

It seems that the likely reason for our images degenerating to mugato-poop in their journey to PACS is the fact that modality vendors use these private tags to add various parameters that are not generally readable by a PACS from a different vendor! As described by Donald Peck, Ph.D., in a lecture for the American Association of Physics in Medicine,

. . .you can use them to display almost any tag as an annotation, also they include acquisition and processing parameters inside of the DICOM header. These processing parameters though are often stored in what’s called private tags, which are proprietary to the vendor and may or may not be visible inside of your PACS system.

This supposedly is a way to make you want to buy all your toys from the same company, but no one told the salespeople about this, or the service engineers for that matter. They subsequently flail around trying first to point fingers at the PACS involved, and when that doesn’t work, they attempt to fix a problem that turns out to be intrinsic to their scanner. But it is the way it is. Does this interfere with the image enough to cause a miss? To answer that, we would have to compare each and every study as displayed on the MR console and on PACS, and that ain’t going to happen. But we’re still going to worry about it.

This situation dovetails into the larger discussion of proprietary fields/private tags in DICOM in general. Why are they even there? Michael Gray, on his website, describes the example of Presentation States and Key Image Notes as illustrative of the Proprietary Problem:

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 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.

. . .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.

Amen. Sadly, it is next to impossible to find a scanner OR a PACS that doesn’t dabble in this unfortunate practice. Maybe if we users started demanding such products, the vendors would provide them. OK, I’m demanding it. And so should you. Let’s start a private, little war on Private Tags.


Our GE rep (who is NOT pictured above, by the way) sent in these responses to our complaints. Our notes are in black, the GE responses are in green (of course!):

Issue #1:
“In my (Dalai’s note–PACS IT expert) experience, GE as well as some other vendors, are notorious for placing key information in proprietary fields outside the DICOM standards. This creates a marketable advantage for the vendor to sell other related products in their product line.”

When the original DICOM standard was developed for the MR image object, there were few fields defined. As MR has evolved these standard fields have become insufficient to contain the data necessary to annotate our images to the level we currently support. The enhanced MR image object has defined many more standard fields to better align the image object with current technology. At this time GE only supports the original MR image object. At this time no date has been set to support the new MR DICOM object. However, GE provides details on each of the private fields for our MR object in our DICOM conformance statement. When requested, additional details are provided on how the private data maps to annotation fields on the image. As far as selling related products, the only GE products which interpret MR private data fields is the CT system and the Advantage Windows. The GE PACS does not interpret private GE fields any better than it interprets competitors private data.

Issue #2:
“Why do the MRs on the GE scanner look so much better on the MR console than they do the Agfa PACS?”
In general I would expect a PACS viewer (which is designed specifically for displaying images) to have a better display then the MR scanner. I suspect that there is a calibration difference between the Agfa PACS monitor and the GE MR system monitor. I would suggest you take a representative image on the MR and set its window & level to optimum display on the scanner. Record the WW/WL values. Then send the image to the PACS and re-adjust for optimum viewing on that display station. Record the WW/WL values again. What are the differences? When adjusted for optimum display on each station, is the MR monitors image still better?

Well, the answer to Issue #1 is pretty clear, and makes sense to GE, I’m sure. It’s easier to stick to an old standard and the software band-aides that have evolved over the years to deal with the limitations of the OLD standard, than to migrate to the new standard that would handle the problem. Maybe. I’m encouraged to know that Centricity wouldn’t deal with this any better than any other PACS. Actually, I’m pretty discouraged. The implication is that the internal standards are available to the PACS vendors via the DICOM statement, and they should feel free to rewrite their viewing software to accommodate this, um, individuality of GE’s private tags. I guess the PACS vendors could take a Microsoft Windows Plug-and-Play approach, gathering all parameters on all possible scanners to create a brute-force, comprehensive compilation that would let their PACS read all private tags of all vendors. Sounds pretty daunting to me. Why not just create a standard that all scanners could follow? Wait, we already have one…..

As for monitor calibration, I’m not buying that one. Why would the images from various CR’s, sonograms, scintigrams, R&F rooms look OK, and the MR’s not? I’m guessing that we are to adjust some sort of mapping of window and level settings between the scanner and the PACS, but that sounds sort of kludgy to me. Maybe DR’s Catapult system is the answer here, wherein the technologist has to adjust the image within PACS for optimum viewing before sending it on to the docs. But frankly, this still sounds like finger-pointing, when the real problem is those pesky private tags.
It’s still time for a private little war on Private Tags.

At Least He Has His Priorities Straight!

eBay seller clydekat is trying to sell off his 10,000 sets of Star Trek Lenticular Motion Cards. This amounts to about 40,000 of these trading cards. He is asking what is, I suppose, a reasonable price of $11,999.99. But, there appears to be a problem, or maybe an added bonus….If you examine the ad very closely, you will see in the subtitle, “MUST SELL WIFE”! He doesn’t specify how much shipping is on the wife, though.

The real story is that “The wife is making me clear out the extra room for the baby, imagine that!” After this, I have a feeling clydekat will be cleared out himself.

Be careful how you word your eBay listings!

Centricity and Linux (and IntegradWeb)

Our Centricity site has been waiting to upgrade from version 2.x to 3.x for a while. We had an intermediate upgrade recently, but we’re still in the 2.x’s. The PACS administrator was just informed that (surprize!) the jump to 3.x will require new hardware, because the new back-end uses Linux.

This isn’t a total shock, really, given the fact that GE uses Linux in other products, such as the Advantage Workstation (the beloved AW), as well as within the consoles of several scanners. Not only is Linux cheaper than Windows (they use the Red Hat flavor), but it is more robust as well. It is reasonable for them to do some back end migration to this platform, especially since at one time or another, there has been everything from Sun Unix to Mac OS bundled in there somewhere.

Ah, but here is the problem we face. At this point, we don’t know how much this hardware upgrade is going to cost. AND, we aren’t really all that sure how long the Centricity product will continue, given the recent acquisition of Dynamic Imaging and the incorporation of its IntegradWeb program. At some point, depending upon how much hardware (and software for that matter) the upgrade will require, the balance sheet tips in the favor of simply replacing the old Centricity 2.x with the new IntegradWeb. I’m hoping that migration of several years of data from on to the other won’t be a big problem. If it is, there really might not be a reason to upgrade at all, except to keep the whiney radiologists happy. And eventually, there might not be a reason to migrate within the GE family altogether.

Anybody out there know any details about these upgrades and migrations? I suppose GE will tell us sooner or later…..

Is Speech Recognition a Kickback? Maybe….

In a post from last year, I asked this question on behalf of a reader. When posted on AuntMinnie.com as well, there was nothing but laughter. To repeat the original query,

Do you know if anyone has ever tried to construe the adoption of voice recognition technology as a kickback to the hospital in violation of federal antikickback statutes? It would seem to me that transcription services are traditionally provided for free by the hospital to hospital-based physicians (except of course the cardiologists and administrators don’t have to use it!) and that the cost of transcription is covered by the technical fee collected by the hospital. In essence we are providing free services to the hospital in return for a hospital contract. I wonder what the lawyers would say.

Well, writing in the current JACR, Richard Duszak Jr., M.D., restates the question, and comes to some disturbing conclusions. At best, this is a gray area, and at worst, it is indeed a kickback, subject to some rather strong penalties.

According to CMS,

“[N]o one involved with the processes of developing either the radiologist or physician fee schedule made a decision that would have specifically placed transcription costs in the [professional component payment]” [4]. And, even more definitively, “there is no question that costs incurred by the hospital for the transcription of interpretations are allowable operating costs for the purposes of intermediary payments” [5]. When hospitals are paid by Medicare intermediaries for the technical part of imaging services, historical documents indicate that they are unequivocally being paid for the costs of associated transcription services.

Keep in mind that

The federal antikickback statute makes it illegal to solicit, receive, offer, or pay any remuneration for referring a service for which payment is made by a federal health care program.

Because hospitals are reimbursed by Medicare for transcription expenses as part of their normal technical charges, they potentially run afoul of the antikickback law if they “double dip” and collect those same transcription costs from their radiologists, who necessarily receive referrals of Medicare patients from those hospitals. In such a scenario, the amount charged to radiologists for transcription costs could not possibly represent fair market value, because those transcription services are already being reimbursed by Medicare.

Now, enter Speech (OK, Voice) Recognition:

Depending on the specific circumstances of implementation, VR technology also creates antikickback concerns with regard to radiologists’ making in-kind payments to hospitals for transcription services. Even advocates of VR technology acknowledge that “it transfers a task to radiologists that previously was performed by transcriptionists” [11]: work for which Medicare is already paying the hospital. That transfer of “secretarial duties” comes at the very real cost of increased work time to radiologists [12].

If . . . radiologists are forced by a hospital, as a condition of maintaining their professional services contracts (and hence continuing Medicare referrals), to assume all the secretarial duties of now laid off hospital transcriptionists, jeopardy more likely exists.

This is called double-dipping, and it is a big no-no. So, keep this all in mind if you feel forced to accept SR in your practice.

I Miss Ronnie

I rarely dabble in politics here on the blog, although I might get into a fight or two on AuntMinnie.com’s “Off Topic” forum. However, a friend forwarded me these quotes from the late President Ronald Reagan, and I have to share them with you. They are all-too pertinent in today’s political quagmire, and they speak for themselves, requiring no interpretation from me.

“Here’s my strategy on the Cold War: We win, they lose.”

“The most terrifying words in the English language are: I’m from the government and I’m here to help.”

“The trouble with our liberal friends is not that they’re ignorant; it’s just that they know so much that isn’t so.”

“Of the four wars in my lifetime, none came about because the U.S. was too strong.”

“I have wondered at times about what the Ten Commandments would have looked like if Moses had run them through the U.S. Congress.”

“The taxpayer: That’s someone who works for the federal government but doesn’t have to take the civil service examination.”

“Government is like a baby: An alimentary canal with a big appetite at one end and no sense of responsibility at the other.”

“The nearest thing to eternal life we will ever see on this earth is a government program.”

“I’ve laid down the law, though, to everyone from now on about anything that happens: no matter what time it is, wake me, even if it’s in the middle of a Cabinet meeting.”

“It has been said that politics is the second oldest profession. I have learned that it bears a striking resemblance to the first.”

“Government’s view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.”

“Politics is not a bad profession. If you succeed, there are many rewards; if you disgrace yourself, you can always write a book.”

“No arsenal, or no weapon in the arsenals of the world, is as formidable as the will and moral courage of free men and women.”

“If we ever forget that we’re one nation under God, then we will be a nation gone under.”

1000 X-rays

I have got to get a Wii!

AuntMinnie.com reviewed a study published in the Annals of Emergency Medicine which I find rather disturbing. It seems that if you are so unfortunate as to experience trauma and fortunate enough to make it to a trauma center alive, you will be the likely recipient of a “pan-scan” of the head, neck, chest, abdomen, and pelvis. At our local trauma center, we call it a “man-scan” with no offense to the ladies, and it generally includes a scan or two of the extremities as well as regular old radiographs of all areas in question. There is a lot to be said for this approach, as the victim of polytrauma will most certainly have multiple injuries, and CT is very good at ferreting them out. The man-scans can be very tedious to read: “There are minimally displaced fractures of the 3rd, 4th, 7th, 9th,10th, and 12th ribs on the right and……”

But use of this powerful tool has its price, and that is in terms of radiation, as well as the final bill. it seems that the average trauma patient is exposed to radiation equivalent to 1,005 chest x-rays, which is enough to raise the individual’s risk of developing a malignancy later in life. While the average person in the US receives a dose of about 3 millisieverts (mSv) from environmental sources (radon, cosmic rays, friends with glowing personalities, etc.), the star of the trauma imaging show receives an average dose of 40 mSv, and gets it all at once.

What to do? The study’s author suggests:

Possible options for reducing radiation exposure may include ordering fewer repeated imaging studies, using lower dose radiological imaging techniques and using alternative imaging methods that do not use radiation, such as ultrasound and magnetic resonance imaging.

I think that there also has to be a little cerebral activity injected into the decision process. It is all too easy to order a shotgun battery of tests as a knee-jerk response to a trauma situation, without completely evaluating if some components are necessary. I realize that I’m not on the front line here, so to speak, and the folks that order the tests are. Still, I think they have to be made aware of the fact that the “man-scan” might not be quite as benign as we would like to think.