PACS, Workstations, Simple Teleradiology - A Do-It-Yourself Primer|
management book that I recently read, talks about how many companies in the early
and mid-part of the 20th century made money out of "friction", i.e. the lack,
on the part of the customer, of knowledge or information about products, pricing
and competition. With the advent of the Internet and improved information flow,
"friction" has reduced significantly, but not completely.
few weeks ago, speaking to a new company that had developed a DICOM-based viewing
and archival station, I asked why anyone would buy a product that could be bought
free or at minimal cost via the Internet. And the representative too replied,
"as long as people are ignorant, we are in business".
to just three-four years ago, the modality vendor companies (companies selling
CT, MRI, etc) had a stranglehold on the workstation and PACS business, especially
in the third-world countries. Some factors that made it virtually impossible to
develop workstations and PACS solutions at a reasonable cost were:
of understanding of images, proper DICOM-related information
of DICOM-compliant machines
image formats and output devices and
absence of other companies that could provide solutions
three years ago, a simple workstation, bought from a modality vendor would have
cost anywhere between Rs. 7-10 lakhs (20,000-25,0000USD), if PC based and 15-20lakhs
(35,000-45000USD) if Sun Sparc or Silicon-Graphic based.
it is possible to completely bypass the modality vendor companies for developing
simple workstations and mini-PACS systems because of a number of developments.
Modality companies have had to adopt widespread support for DICOM. Access to information
and software via the Internet is improving rapidly.
Internet also provides the ability to communicate through different forums with
other radiologists to understand the pros and cons of these companies and their
software products. And finally we have the reducing costs of powerful PCs and
are also now many other focussed companies that can deliver workstation and PACS
solutions to individuals and hospitals. These include the camera/printer companies
and dedicated workstation and PACS companies, which are all competitors in this
these companies however are expensive for developing simple archival and viewing
stations, when it comes to ordinary users in third-world countries,
article therefore is aimed at small hospitals, individual private practices and
even government hospitals, which are fund-deprived, and want to develop their
is aimed at those radiologists who are a little computer savvy or have computer
savvy people working with them or for them and who can use the Internet and locally
available resources to their benefit. Even computer un-savvy radiologists can
do this with a little help from their "friendly neighborhood" computer vendor
or networking specialist, who luckily thanks to the computer and last year's dot-com
revolution are available by the dozen, even in small towns.
after understanding what is involved in setting up such a system, radiologists
may still opt to deal with a company (for "peace-of-mind" and "support"), rather
than to develop their own solutions. Hopefully, the knowledge gained from this
article may allow them to leverage with these companies better.
Terminology and a Few Definitions
we go ahead with the step-by-step description of what is involved in developing
simple viewing and archival stations and workstations, I would like to run through
some basic terminology.
system capable of generating an image. E.g. CT, MR, USG, X-ray (with CR or DR
systems) and even pathology, ECG, etc.
is the output device either film-based or paper-based. If the camera/printer is
part of the DICOM network, any modality in the network can print to the camera/printer
even without a direct cable connection between the camera/printer and the modality.
DICOM - Digital Communications in Medicine
standard partly created by ACR-NEMA in conjunction with various vendors. It defines
the structure of an image in terms of its headers and the image component. We
do not need to actually understand the technicalities of this. The images are
usually saved as .dcm images.
DICOM Compliance Statement
statement that modality vendors make, defining how compliant they are with DICOM
standards. As a rule, American and European companies are more DICOM compliant
than Japanese companies
DICOM Print, Send, Receive, Store
functions based on the DICOM image that the various machines should have. Some
of the earlier machines may have some of these, but not all. Many times, even
if the functions are present, the vendors don't explain this to or "hide" their
presence from their customers
Ethernet, LAN & TCP/IP
stands for Local Area Network and implies the presence of two or more computers
that are networked together; i.e. they communicate with each other, using Ethernet
cards and cables. Wireless connections are also now possible. "TCP/IP" is the
usual protocol used by an Ethernet based LAN for facilitating communication between
the various computers. TCP/IP is incidentally also the protocol used to connect
to the Internet.
PACS (Picture Archival and Communications Systems)
a simplistic sense, a PACS would imply any solution that allows archival of images
and communication between two systems, whether it is between two or more modalities
or between modality(s) and a viewing station. A printer/camera is also part of
an Undertaking from the Modality Vendor for Basic Support
we buy DICOM ready machines, it is necessary to get in writing from the vendor,
they it will support DICOM connectivity. DICOM Send, Receive, Print and Store
should be available and an Ethernet port should be available. If the camera is
going to be on the DICOM network, then all this will be available by default.
We should get the camera engineers and the modality engineers to talk in advance
so that their respective needs are understood; the camera engineers will see to
it that the modality has what it needs for the DICOM network.
of the camera vendor though, the modality vendor must be made to commit to support
DICOM connectivity. There are many reasons for this. When images have to be sent
from the modality to the workstation, it may be necessary to enter the service
mode on the modality, to define and identify the workstation computer, to set
TCP/IP settings and to configure certain ports. We need engineers from the modality
vendor to enter the service mode. Some companies have extremely user-unfriendly
interfaces and it makes sense to have the company engineers around. It may also
be a good idea to make the camera and modality companies both agree to a couple
of joint sessions in your setup, when the DICOM network is being installed.
Groundwork: Buying a Computer and Setting up a Basic Network
is advisable to buy a new workstation computer rather than to upgrade from an
old one. The type of computer will depend on your needs. If the need is restricted
to viewing and archival, a standard current Pentium III with at least 128MB RAM
and a 20GB hard disk is enough. If we need to install 3D and other software, it
would be advisable to go for a dual Pentium processor with 512MB or 1GB RAM. Irrespective
of the configuration, the computer needs to have an Ethernet card. The OS (operating
software) should preferably be Windows NT workstation or Windows 2000, which are
more stable than Windows 98 or Windows ME. For archival, a good CD-writer is a
must. For viewing, a good 17" or 19" inch monitor is advisable. The computer cost
would range from between Rs. 30,000 to Rs.1,00,000 (1,500-3,000USD) depending
on the configuration.
the installation is new, then the appropriate computer cables should be laid out
from the hub to the various devices that are expected to be on the network. The
hub is a small device that acts as a central "switch-board". Cables from all devices
and computers come to it; information from one computer to another is relayed
through the hub. Typically, the network would consist of the modality computer,
the camera, the workstation computer and all other computers (reporting, patient
registration, doctor's personal computer, etc) depending on the setup. The hub
costs around Rs 10,000. Cables and connectors are not very expensive, It is worth
buying high quality cables and connectors - this will save lot of heartaches later
on, and is a must for data transfer of images
cables are UTP cables with RJ45 gold connectors. These are the best quality for
networks where there is high-value data transfer (large amounts, or high quality
images). The crimping of the cables with connectors should be carried out properly
and cables should run through channels on walls, and not dangle loosely across
computers/hubs. Also ensure that there is adequate space between these data cables
and electrical cables (at least 6" would be ideal).
is of course, not necessary to have a hub or a complex network. A single cable
between the modality and the workstation PC can also suffice, and may be the best
solution in an existing setup where the camera is non-DICOM and/or where laying
cables is a problem.
is also a good idea to involve a local computer person with networking experience;
these as I said earlier, are available by the dozen and the person who sells you
your computer (unless you are buying branded PCs), will also provide this support
at minimal to no extra cost. The local person/company can thus work with the interior
decorator or electrician to ensure correct laying of the cables and make sure
that the network is functioning correctly, at least between the workstation computer
and the other PCs such as the reporting or patient registration PC.