Living With DICOM: Imaging modality manufacturers and PACS vendors have moved far beyond where they were just a few years ago in getting their DICOM-dependent equipment to communicate.
"Once you get past the installation stage
Talk to BMETs and other radiology service technicians about the hurdles of DICOM
(digital imaging and communication in medicine) when it comes to PACS (picture archiving
and communications system) operation and sooner more likely than later you will hear that
phrase.
It is a good thing in one way. It means that imaging-modality manufacturers and PACS
vendors are way ahead of where they were a few years ago in getting their DICOM-dependent
pieces of equipment to talk to one another. But there are still problemssometimes
big problemswith DICOM from a BMETs perspective, both during and after
installation.
DICOM is a code or a standard that has been adopted by manufacturers of imaging
equipment to create consistent images and let imaging systems that must be interfaced talk
to one another. It is the language that lets an MRI or CT scanner transmit images over a
PACS so that radiologists can sit at workstations and interpret the images electronically.
But DICOM is more than a communications standard. It is an evolving world unto itself.
The DICOM rules are continually under review and revision by a committee that operates
under the auspices of NEMA (National Electrical Manufacturers Association) and the ACR
(American College of Radiology). Over its evolution DICOM has gone through a number of
versions, but it has stabilized on version 3.0. Some would say more-or-less stabilized.
The only difficulty I have experienced has been with installation problems,
says Christopher L. Jones, Sr, BMET, MCP.
With the new DICOM standards it is more consistent, Jones adds. The
way all the manufacturers have got together on one standard is great. With the earlier
versions there were printing problems with the different modalities going in. They had
different DICOM versions but also different languages of the DICOM going in.
Respondents for this story generally agree with Jones that DICOM with a basic uniform
3.0 is far ahead of the recent past when technicians hardly knew what DICOM renditions
would show up. Even within version 3.0, however, there are subsets of coding that are not
uniform and that still cause BMETs and other technicians long nights of tinkering and long
days of pleading with vendors to make adjustments.
Phil Mininni works for Genesis Technology and is assigned to the Nebraska Medical
Center in Omaha. If I do have DICOM problems its usually after a new piece of
equipment has been brought in. There are conventions that everybody is supposed to use,
but not all DICOM 3.0 is the same. When one vendor says they are 3.0-compatible, they may
send the data in a slightly different way than the receiving end is looking for in the
header. Sometimes the receiver doesnt talk to the modality, and then you have a
blame fight between one vendor and another.
Tags Different
Tim ODell, RT(R), is imaging project manager at Banner Health, a hospital
network in Arizona. He is assigned to projectsincluding a series of PACS installs
that will conclude in 2006at six hospitals in the Phoenix area.
There is so much that falls under DICOM that hardly anybody knows what it
is, he says. For most DICOM 3.0, most vendors have functionality. The problems
are usually not talk problems. Theyre more related to tags and the other
information below the header.
The tag could be pixel spacing, it could be annotation. Everything you see on an
image is some kind of tag. Not all vendors use the same tag for the same thing. They have
to map to their own software, so they basically take overlays that are generic to their
system, which is what they think the user likes to see. But some things you would normally
see on the film dont show up on the PACS. Were sending it and its not
showing up on the PACS.
So then you get copies of the DICOM conformance statements. You have to do a
DICOM dump. You dump that image into a DICOM format so you can see what is mapped.
ODell is right about the complexity of DICOM. The NEMA Web site (www.nema.org) offers 17 manuals on DICOM. The manuals range
in price from the high double to the low triple digits. [A free soft-copy version of the
DICOM standards can be downloaded from the DICOM Web site (www.medical.nema.org).]
When the problems have been isolated, ODell says, that is when technicians have
to turn to the vendors.
You may have to go to the modality vendor and say Can you change these
fields? But its on the PACS side where things are usually remapped, he
says. Its not as easy as it sounds. The PACS vendor usually wants to charge
for it.
ODell also says the process of making changes can take weeks or months. He
cautions against taking as gospel vendors assurances that systems will interoperate.
New DICOM standards
provide consistent communication.
They all tell you there wont be an issue, but they dont get into the
detail of image tags in their evaluations. Its sort of been a lesson learned on my
part. You have to get the DICOM conformance statements from the PACS and modality vendors.
They are required by law to give them to you. Then you can at least go through and map
what is being sent on what tag.
Radiology Impact
If radiologists or clinicians who are accustomed to being able to measure on film find
they cannot do so on PACS because the tag variations wont allow it (an example
ODell uses) or if other DICOM problems arise, it is usually the technicians who are
in the line of fire.
Michael Ellis, BMET, performs PACS servicing and repair for the three-facility Freeman
Health System in Joplin, Mo.
Ellis says one of his toughest hurdles has been the radiologists and their
expectations. They think that everything is so easy. They are very demanding. They
dont know whats involved and sometimes I think they dont care.
This was particularly true when he was under pressure to move DICOM images to a new
night-reading radiology service with which the Freeman doctors had contracted. We
had our virtual private network tunnel go down. The nighthawks would hit a switch and it
would lock up our system. I was up until 2:00 AM fixing problems.
Still when system glitches occur it is often the radiology workflow that suffers most
and that can translate into less than optimum patient care. Sometimes it isnt just
biomedical personnel and radiologists who get caught up in turf and culpability battles.
Michael Backof is a DICOM consultant for the main support group at the US Department of
Veterans Affairs. He is stationed in Maryland and troubleshoots PACS installations
throughout the VA system. He says information technologists can also be part of a
three-way conflict between doctors, biomeds, and information technology departments.
The biggest [problem] I run into, Backof says, is the animosity
between radiology and IT. Thats one thing that makes a lot of the PACS
implementations so hard. IT is not sympathetic to the workflow of the radiologists. They
treat it just like any other hospital department. Backof says, this support
responsibility has been ours, and now you get the IT people edging in on it, but the
VA says IT will support the PACS. In the commercial world the PACS support is more the
responsibility of radiology.
Backof agrees that most of the problems with DICOM occur during an installation. Like
ODell, he blames vendors for inserting proprietary tags into the DICOM format.
The thing you run into is private tags or enhancements in their software so their
equipment only works with their other equipment. Usually, there is a low-level basic mode
with thumbnail images, look-up tables, and things like that removed that can be configured
between devices (for all vendors), and then everything talks.
Education
ODell advises every hospital or health network linked with a PACS to develop an
on-staff DICOM expert. He says there are a lot of DICOM classes available to BMETs and
other technicians, and there is a lot of free information on the Internet, including
software to troubleshoot DICOM interfaces.
We assume too much that the vendor is going to do all the work up front for us.
We need to get more people to DICOM classes, he says.
Herman Oosterwijk couldnt agree more. Oosterwijk is founder and president of
OTech Inc, a Dallas-based educational firm that runs DICOM classes, among others. He has
also published a book, DICOM Basics, which, he says, is not intended to be a comprehensive
handbook or programmers guide for DICOM software implementers. Rather, it is a
simple reference for people who like to understand the basics of the DICOM standard.
Oosterwijk says he is puzzled by a lower-than-expected turnout to his DICOM classes
given that the BMET or other technician is so important to proper PACS functioning.
PACS provides images
at a keystroke.
Poor DICOM will break the workflow, he says. People then have to do
things manually. Nobody in the typical hospital knows anything about DICOM, and they rely
on the vendors to help them. Then it boils down to the vendors not doing their job.
Oosterwijk says a lot of the problem isnt vendors, though. Its poorly
trained technicians at the hospitals. The service engineers often have no training
in DICOM. More than half of all service engineers have no comprehension of DICOM. Those
who come to my classes have no clue.
Despite the need for training, the number of individuals who show up for study has
actually fallen off in the past couple of years, Oosterwijk says. I dont see a
flood of students, and I really dont know why. Its not always clear that the
companies are taking any action to train.
A decade ago x-ray technicians mostly just needed to know their modalities, he adds.
But now you have to know so much more. The modalities are a lot more software
intense and you need to know about integration.
Im in the field a lot, he says, and some PACS installations hum
along. In those cases it is the service engineer, always. These people are extremely
important to the operation of the system, and PACS needs a lot of TLC. These systems are
not maintenance light.
Greg Swigart, BMET, is one who took up the educational challenge. He troubleshoots
radiology equipment for the St. Lukes Hospital system in Bethlehem, Pa, a
four-hospital network. He took a series of classes that included material on DICOM.
My director had the vision for us to be able to handle the radiology problems
in-house, he says, but we had to convince the radiology management and senior
technologists that place the service calls that we could handle them. I began making
myself visible and asking Is anything wrong? It took a while for the
radiologists to accept my being able to do that.
Once they were convinced, Swigart says, the hospitals lowered the level of their
maintenance contracts on imaging equipment from a full vendor contract to a support
contract.
Swigart is just one of about 14 biomedical technicians deployed in the four hospitals.
It used to take an hour or two to get to the vendors, Swigart says. Now
the radiology departments call us, and were there in 10 minutes. We plan to educate
ourselves enough so that when the warranties on the PACS equipment run out, well be
able to give the same response.
George Wiley is a contributing writer for 24x7.