Wednesday, April 2, 2008

Requirements for an "office imaging system" for requesting practitioners

Summary: Film is dying but requesting doctors hate loading slow and unpredictable CDs; they need pre-loaded images on a system in their office; specific requirements for such systems are defined; there is no need for them to be expensive or complex.

Long Version.

Doctors, much like everyone else on the planet, crave instant gratification. If it takes more than a negligible amount of time to gather information in the context of seeing a patient, they either won't bother or will become irritated. And after all, even in a salaried setting, time is (somebody's) money.

In the pre-digital days, it often took more time than it was worth to bother to extract and hang films properly, or even find a real view box, hence the frequent sight of films held up to the nearest window or fluorescent light, hardly optimal viewing conditions. Radiologists, with a more pressing need to view the films "properly" and in bulk, addressed the film handling problem with pre-loaded panel viewers on which trained but relatively low cost staff "hung" the films in advance. Some radiologists rarely lifted their foot off the pedal as the films scrolled mechanically by whilst they dictated rapidly.

During the transition to soft-copy interpretation of digitally acquired images, the importance of effective work lists and hanging protocols to efficiently report increasingly complicated large studies has been obvious to radiologists. Such features are a vital component of any modern PACS. In an inpatient setting, or an ambulatory clinic attached to a large facility that does its own image acquisition, an enterprise-wide PACS can (in theory) provide ready access to images when and where they are needed, in an appropriate presentation, whether it be in the examination room in the clinic, in the operating theatre, or somewhere convenient during ward rounds. Where appropriate, dedicated staff are deployed to optimize the performance of the process when it cannot be totally automated.

Yet in a traditional ambulatory environment, in which radiology facilities and requesting practitioners office are geographically and organizationally separated, as films disappear and imaging centers insist on handing out CDs to outpatients instead, there is a growing problem.

For the busy doctor, CDs suck; there is just no question about it. They are relatively slow to load, regardless of how fast the drive is, they usually have some awful viewer that one is not familiar with and which takes a while to start (making the process even slower) or fails to work. Once started, there is usually no clue which images are important out of the hundreds or thousands present. Even though these CDs are increasingly standard DICOM and IHE PDI compliant as the vendors finally get their act together (with a few notable and reprehensible exceptions), and there is talk of faster, higher capacity media (DVD and even USB memory sticks), that doesn't get around the fundamental problem that handling and loading physical media "on demand" is inherently troublesome.

The key issue is the handling and loading of the media. The obvious solution is to pre-load it.

When a patient is referred to a large facility with a PACS, whether it be for a specialist consultation or further imaging, typically any "prior" films and CDs will be requested in advance, and these will be pre-loaded into the PACS, so that they are available for review and comparison using the normal tools and work flow. Any necessary "import reconciliation" of foreign patient identifiers will be performed, etc.

Clearly, a scaled down version of this process would be feasible in a small office, even for a solo practitioner. Patients do not walk directly off the street into the examining room. There is always some sort of reception facility. At that time, a clerk could take the media and "import" it into a system of some sort. This would require no technical expertise, and the media would either load successfully (if it were DICOM and IHE PDI) or not (if it were proprietary Philips/Stentor or Amicas rubbish). Loading an entire CD should take no more than a matter of a few minutes. If the receptionist was really busy, then a dedicated staff person might be necessary. Media that failed to load would be dealt with by clerical staff interacting with the offending imaging center, which argues for having the media sent in advance of the patient's visit if at all possible.

Reconciliation of identifiers could be performed automatically (if the imaging center's numbering scheme was recognized), or semi-automatically (by patient name matching confirmed by the clerk), or manually (by typing in or selecting from a list of scheduled patients) as required.

Perhaps the report (quite likely not on the CD, and perhaps faxed separately), would also be scanned into the system, or be available in whatever electronic document handling system the practice used, or perhaps just be present in the paper chart in the old fashioned way.

The images would now live on a fast central server in the office, and be available anywhere the necessary display hardware and software was located. Prior images might or might not also be archived on the system, but the primary goal here is to describe how to make images available, not address questions of whether or not and how the requesting practitioner should archive them.

Ideally, every exam room would be equipped with an appropriate display, perhaps just a reasonable sized color LCD, unless the specialist practice was of a type that demanded a high intensity calibrated grayscale display. As is standard security practice, the display would need to be blanked and locked unless the doctor was in the room and then only the appropriate patient's images would be visible. For example, the doctor could apply their finger to a biometric keypad to activate the system, which would then display nothing until the patient's ID from the paper chart was read with a bar-code wand, at which time the images would instantly appear, preferably jumping directly to the key images if they had been flagged as such on the CD in the first place (using the standard DICOM objects for this purpose). One could imagine ways to use RFID tags creatively to make this almost totally automatic, with the presence of both the patient and the doctors RFID tags in the room activating the display automatically.

The doctor would already be familiar with the "viewer" since it would not be the one on the CD but rather whatever was installed on the system and on which they were trained. It would have the necessary features that they had chosen (such as orthopedic templates or 3D cardiac visualization or whatever, depending on their specialty).

Exactly the same strategy can be applied in the operating theatre, whether it be in an inpatient setting in the absence of an enterprise PACS, or for outpatient surgery. Images should be preloaded and made available in the OR to which the patient is assigned or in which they are currently located. The physical type, mounting and interaction with displays is more complex, but these issues are not specific to this discussion.

How hard or expensive would all this be ? It is pretty straightforward really , when one considers the simple work flow and similarity to existing systems. The use of off-the-shelf consumer computer, display, network, biometric and bar-code hardware and software could make this very low cost. There are obviously already free and open source tools to implement this if one is technically sophisticated, and there are no doubt already commercial systems that are designed for this purpose or which could be re-purposed easily enough. One could clearly add potentially expensive bells and whistles like integrating with practice management systems, room scheduling systems, electronic medical record systems and the like, as desired.

In future, as Internet transfer of images directly from the imaging center to the recipient's system becomes commonplace, this mechanism could replace CDs as the transport media. Still though, the images should be ready to view on the local system, and there should be no need for the physician to wait to load them on demand from some off-site local over a relatively slow connection, or be forced to learn how to use whatever web-deployed client that particular imaging center used.

To repeat the key message, regardless of the transport mechanism, the requesting practitioner should have the images pre-loaded on their own system and accessible to them at the point of care instantaneously and using their own preferred tools.

The bottom line is that there are few excuses for whining about "slow" media or problematic viewers, when a small investment in each user's office could produce a near optimal solution.



MS said...


In our situation, this is completely unrealistic at the moment. We need IHE compliance, and although many Surgeons have computers on their desks, they will not be of a standard that will be suitable for image viewing.

Surgeons can be accused of being tight or luddites, but there are insufficient improvements in hte digital move to enthuse clinicians and encourage them to provide the investment. I have tried pre-loading. I have set up links at the reception desk, organised work flow systems, and tried it as an option, but a real step backwards.

The current system with film, for surgeons is fine, and apart form CT and MR, digital confers no advantage. I have some solutions, and I think we may be able to provide a trial system that will work well.

As you are aware of the system here, you will appreciate that although there is more "apparent" regulation, there paradoxically tend to be less interference with practice - as long as you work within the guidelines.

However, as the Government pays the bills, they can set the standards. The have been rather concerned about the issues that the digital move has created, and will be have less trouble in imposing IHE etc.

I can send you some more specific documents if you are interested, but I do not see it as a very complicated problem in principle, as long as the defined requirements are clear.

Michael S

David Clunie said...

Michael S wrote:

"I have tried pre-loading. I have set up links at the reception desk, organised work flow systems, and tried it as an option, but a real step backwards."

This is what I really would be interested in hearing about ... why did this not work for you and why was it a step backward ? The specifics are of considerable interest to me.

"The current system with film, for surgeons is fine, and apart form CT and MR, digital confers no advantage."

Well, there are two obvious problems with this; one does need to deal effectively with CT and MR, and for plain x-rays from sites with CR/DX and PACS, folks are just not going to get film any more, so they have to get over it, whether it is of benefit to them or not. If for now other reason than the film companies are going to stop making the film.


David Clunie said...

Here is the text of a comment on this thread of discussion that had continued on Aunt Minnie:

Michael wrote:

"A short question, and an indication of potential problems. I have patients now that may have 6 or 10 studies. A few chest x-rays, a back, CT and MRI and a Bone Scan etc. If I am not on a LAN would you envisage these scans all being on separate CDs. That means, my secretary will need to load the data off maybe 10 CDs onto my hard drive, to see the latest x-ray, as they will not necessarily know what I need to see. Or do I need to vet all patient studies before they are preloaded to load only the ones I need. That will put a lot of extra data on my computer, and I will then need to go through it and delete what i need. I see about 6 - 8 patients an hour if they are simple cases, and this will really slow me down, or will cut into time i should be spending assessing the patient.

If a patient has weekly x-rays of a fracture, would these go on separate CDs?

Maybe USB drives are not the answer, but functionality for patient care they are way ahead of CDs as a standard, but happy to look at specifics of exactly how you see this working."

Hi Michael

Whether the exchange media is USB or CD makes no difference to the question of whether there is one or multiple exams per piece of media; that is a question of in what order the exams were performed, whether they were all at the same imaging center, whether they practice is to record priors with new exams on the media, etc. If you are expecting everything you want (and nothing else) to be on the USB stick, then somebody has to make it that way, and they could just as easily do the same on a CD.

With what I propose, regardless of the transport media, old exams should presumably already be cached on your "system", so that when new media arrives for the current visit, anything missing from the media is already there and any duplicates are suppressed from visibility. Obviously, for weekly images of a fracture there would be no need to reload the priors from CDs that were loaded last week. Only at the first visit may there be a need to load a lot of stuff, and you can establish a policy for your staff if you want to be selective about what is loaded. For post-operative follow upvisits, a dump of relevant stuff from the hospital PACS over a network connection would be preferable, obviously.

Presumably you are not responsible for long term archiving of the images, nor have a desire to do so; A large cheap off the shelf central disk with a "least recently used" policy for flushing its contents automatically as it approaches full should suffice. What constitutes "large" depends on your volume and proportion of plain x-rays to thin slice 3D CT, but an ordinary 750GB single hard drive can store roughly 70,000 uncompressed 5 megapixel CR images, for instance, and at least three times that with compression, so you would have to be seeing a lot of patients and imaging them a lot to run out of space. Even if you received CDs that were completely full of compressed CT image data, you could still fit over a 1,000 such CDs on a such drive, which costs a few hundred dollars. So, I suggest that the amount of "data on the computer" is irrelevant and not something that you should need to manage. Obviously you can select the size, speed, reliability and security to address the size and scale of your operation.

Obviously, you need not just one computer, but a server of images accessible in a common location (a shared network drive or DICOM server or similar), so that your secretary(ies) can load on import their computer(s) and you (and your colleagues) can view on other computers.

In the absence of a bar coding or room scheduling system to bring up only the patient in the room, you probably want a work list filter in the viewer that shows only "today's" patients, and a viewer that shows the images in hanging protocol order that by default shows what is relevant (e.g., today's image, last week's image and the immediate post-op image).

Avoiding a LAN is not worth considering as an option. On an ordinary switched gigabit copper network you can transfer 2 or 3 of these uncompressed CR images per second, so that should not be a delaying factor, even if the images are not pre-fetched to your own desktop based on worklist and room scheduling information. A LAN confined to your own office systems with a gigabit router between a few computers is also a matter of a few hundred dollars, and any family with more than one computer and a broadband Internet connection at home has such a thing. A wireless setup adds the risk of security mis-configuration and would be slower, but might suffice in some circumstances in which there is a significant obstacle to running wires.

In essence this is a "mini-PACS", with an emphasis on media importation as the source of images, hanging protocols in the viewer configured to your needs, and as much scheduling and work flow information as you can get from either your practice management system or manual entry by your staff.

The bottom line is that with the proper design, the images should already be on your screen as the patient walks into your room, or immediately thereafter, with little or no action on your part, and there certainly should be no need to search of or "vet" anything manually.

The primary barrier to this would seem to be, as Dan pointed out, how to make this so easy to install that it is no harder than buying ordinary computers and installing the usual office productivity software, which almost anyone can do, and making it affordable enough (or free) such that it is tractable to someone who does not want to make more than a trivial investment of money, time or effort in capital or operations.


MS said...


As you can envisage I have been engaged in the discussions at home as well. I guess the key problem, which is embodied in (the need for) the long emails is the incentive to change is just not there for clinicians as we generally have few problems with current film, and there are insufficient advantages to go the the expense and planning to enthusiastically go digital.

As for adding dicom studies to a card, using iQ-VIEW, it will simply add the new studies, and with a DicomDir simply lists all the studies in a simple list which are then very easy and quick to access.

As for film, we are not getting film anyway. Current "film" is just laser printed transparency sheets, and I see this as an interim distribution option for digital, not a continuance of (analog)film. It is a bit of an ongoing con to refer the CR to film in the same vein as traditional analog photographic x-ray film!!!!

I agree companies will soon stop making analog film, but I fear for the small town, third world country hospitals and the like which will be denied the option of x-rays unless they have CR.

The price of solid state media is dropping, and I would say to you radiologist will also have to get over the idea that clinicians will passively accept changes that make life and treating patients more difficult or expensive.

I think Peter MacI is doing a great job pushing IHE. The AsiaPacific Barco Manager visited this week promoting the soon to be released clinical grade (and priced) dicom compliant monitors, we are looking at a BAN (broad area network) floating licences for templating (funded by a generic trade fund), and so the technology is in place. The big gap is the data transfer, and I have no doubt for non-LAN situations, some form of data card will be the case, as 1GB that will hold around multiple studies, is cost effective as a film displacement - and the price is dropping.

As I said, i think it is all very easy, just copy the current work flow, and swap hard for soft, but unless it is more efficient, or better for patient care (not just Rad bottom line) do not expect a ready acceptance by clinicians who have a choice.


Michael s

David Clunie said...

For those who already have or are willing to consider Macs in their office and like Osirix as a viewer, the shared database and self-discovery features make a lot of what I described relatively easy already. Specifically to have staff loading CDs on one machine and physicians viewing them on others is quite straightforward, with minimal if any setup or configuration effort. This workflow is actually described under the category of "Clinician’s Office Workflow" in an Apple white paper "Transforming the Medical Imaging Workflow" written by Roger Katen, M.D. Whilst I am not sure I am convinced by some of the cost and performance comparisons in the paper, there is a lot of interesting information there.

If only some of the other freeware or open source or commercial workstation implementors would implement the self-discovery features that Osirix has championed. The technology is well-standardized, multi-platform and freely available, so why do people not understand that "zero configuration" has enormous benefit for the small office ? If it is good enough for printers, why is it not good enough for workstations ?