Digitization and transfer of images in Radiodiagnosis and Imaging dates back to to early 70s with the advent of Computerized Tomography Scanning, and, subsequently sending these images to cameras and printers hooked on to the machines through a local “network”. Rapid advancements in Information Technology (IT) as well as in the imaging technology have facilitated the healthcare organizations across the world to manage patient's images, records and other data more efficiently. Today, capturing images, archiving and retrieval have already reached great heights, and, further refinements are in progress. The infrastructural requirements for such a venture have to be very finely and judiciously planned well in advance with a view to go filmless as the ultimate objective. Involvement of all concerned and connected agencies is a must e.g. IT, Radiologists, Clinicians and the Vendors.

1. Picture Archiving and Communication Systems (PACS) – A New Paradigm in
Healthcare

2. Review Article
Information Technology (IT) has driven healthcare
delivery to new frontiers. Although radiologists were
exposed to digitization way back in early eighties with the
invention of Computerized Tomography by Hounsfield, it
took quite a while to really reapply the benefits of
digitization. In fact digitization in radiology was way
ahead of the electronic IT boom but took a long time to be
translated into a useful tool to facilitate smooth flow. Roots
of digital imaging can be traced to United States federal
interests. The federal government in USA under the
auspices of the Departments of Defense (DoD) and
Veterans' Affairs drove the movement of PACS into
clinical care, according to Dr Greg T Mogel, an assistant
professor of research radiology at the University of
Southern California. This DoD work was done
domestically to provide continuity of care for a highly
mobile military-dependent population. Internationally, it
came in response to the increasing rate of small-scale
deployments of forces, as in Haiti and Somalia and the
Gulf war.
The recent growth in imaging technology, stressed the
capacity of film-based systems to meet the increasing
needs of radiology departments. Electronic PACS have
been developed in an attempt to provide economical
storage, rapid retrieval of images, access to images
acquired with multiple modalities, and simultaneous
access at multiple sites. Input to a PACS may come from
digital or analog sources (when the latter have been
digitized). A PACS consists primarily of an image
acquisition device (an electronic gateway to the system),
data management system (a specialized computer system
that controls the flow of information on the network),
image storage devices as servers (both short and long-
term archives), transmission network (which serves local
or wide areas), display stations (which include a
computer, text monitor, image monitors, and a user
interface), and devices to produce hard-copy images if
required, (currently, a multiformat or laser camera). The
goals of PACS are to improve operational efficiency
while maintaining or improving diagnostic ability.
What is PACS anyway? The Picture Archiving and
Communication Systems have two very critical functions
embedded in the system which are archiving, and,
communication. It uses networks and computers which
store, retrieve, present, and distribute images in a medical
environment. This storage helps in safeguarding images
and ensures availability for review in future. Traditional
analog department is transformed into a highly functional,
efficient digital environment. No more lost images, no
more degradation of images with time and almost
immediate access for viewing even at remote sites.
BASIC REQUIREMENTS TO IMPLEMENT A
PACSACROSS AN ORGANIZATION
Any Secondary or Tertiary Care Hospital invariably
has Radio diagnostic facilities. The additional
181 Apollo Medicine, Vol. 7, No. 3, September 2010
PICTURE ARCHIVING AND COMMUNICATION SYSTEMS (PACS) –
ANEW PARADIGM IN HEALTHCARE
Dinesh Kapoor
Senior Consultant, Department of Radiodiagnosis, Indraprastha Apollo Hospitals,
Sarita Vihar, New Delhi 110 076, India.
E-mail:din_kap@hotmail.com
Digitization and transfer of images in Radiodiagnosis and Imaging dates back to to early 70s with the advent of
Computerized Tomography Scanning, and, subsequently sending these images to cameras and printers
hooked on to the machines through a local "network". Rapid advancements in Information Technology (IT) as
well as in the imaging technology have facilitated the healthcare organizations across the world to manage
patients' images, records and other data more efficiently. Today, capturing images, archiving and retrieval have
already reached great heights, and, further refinements are in progress. The infrastructural requirements for
such a venture have to be very finely and judiciously planned well in advance with a view to go filmless as the
ultimate objective. Involvement of all concerned and connected agencies is a must e.g. IT, Radiologists,
Clinicians and the Vendors.
Key words: PACS, Digital Imaging Communication (DICOM), Filmless, LocalArea Network (LAN), Radiology
department.

3. Apollo Medicine, Vol. 7, No. 3, September 2010 182
Review Article
requirements for setting up PACS would be:
(i) Equipments must be DICOM compliant.
(ii) Some of non-compliant equipments could/may still
be used with addition of DICOM software on CDs.
(iii) DICOM is the industry standard messaging format
for digital imaging-it was established by NEMA
(National Electrical Manufacturers Association) and
is routinely reviewed and updated.
(iv) DICOM files can be recognized by the extension
“.dcm”.
(v) Connecting the PACS to RIS, HIS, EHR, and/or
EMR can be accomplished through HL7 interfacing.
• A PACS server will receive studies from
equipments, store them, allow queries or
retrieval, archive, and, allow automated routing
• DICOM workstations will be required for use by
the Radiologists for viewing, processing,
analyzing, and reporting the studies
• A good quality network to connect equipments,
PACS server and DICOM workstations. Multiple
vendors may be involved but they must have the
capability of seamless interfacing to avoid any
cracks.
• Storage and backup infrastructure for reliable
storage of the studies carried out.
• Disaster recovery server preferably at a remote
location with adequate redundancy.
A qualified vendor support on site well before the
PACS system live date must be insisted upon. And also
plan on reduced elective patient load during initial system
live period. A training team must be identified and trained
expertly prior to general staff training. Super users/
trainers should be given reduced clinical responsibilities
to allow them adequate time to learn and master the new
systems. Training sessions should be well structured and
available to all staff and potential users. If there will be
remote users, training needs to be planned and performed
for them as well.
Unless the PACS is being installed in a brand-new
facility, there is going to be a repository of old images.
Physicians will want to see these images for
comparison studies. The decision then becomes how to
manage the repository images. The most common
situation is to have a library full of film. Some vendors
provide film digitizers to make a digital image of the film,
which then gets stored in the PACS.
Typical system workflow
The equipments in the department viz CT, MRI,
Conventional Radiology, Mammography, Fluoroscopy,
Ultrasound Nuclear Medicine, DSA, and Cath Labs are
used to acquire images. Images are sent to PACS via
modalities from the RIS system which connects all the
radiology equipment.
• Images received are processed using raw data
information to create image data-base.
• Images are stored in archive device(s). These must be
of a capacity to be able to store images over a very
long period of time preferably upto 5yrs or so, as
images and medical records must be stored legally
for that duration.
• Images are routed to requested devices to include
historical info like clinical details and patient
demographics, if requested.
• Time limits apply compression and move images
between different local CACHE (memory), short
term storage, and long term storage.
• Modalities and conversion systems must configure
PACS as a destination using the correct AE title
(Application Entity), IP address (Internet Protocol),
and TCP Port (Transmission Control Protocol). In a
non-technical sense, you can think of an AE title as a
building, the IP address as the address of a specific
business in the building, and the TCP ports are
individual offices within that business.
• Eventually images are viewed at the viewing
workstations or at the remote client Desktops. The
viewing workstation is where users can query for,
select, and call up images for display, mark-up,
interpretation, reference, post processing and
measurements Etc. It is recommended that the
diagnostic workstations are equipped with
diagnostic grade display systems e.g. typically a
mammogram would best be viewed at 5mega pixels
to avoid any misses.
A very critical aspect to consider is, redundancy. At
least two or three copies of the images must be stored in
compartments or remote servers. Redundancy is a must for
digital imaging as a system down effectively equals care
delivery disruption. All systems related to digital imaging
should be configured with redundancy in mind for archive
integrity as well. Once the systems are in place and “Go

4. Review Article
183 Apollo Medicine, Vol. 7, No. 3, September 2010
live” gets closer, testing should be well underway for any
interfacing between systems… required messaging
between systems should be proven operational before live
date as otherwise it turns into a very painful experience.
PACS technology has been changing quite rapidly.
Initially it was newer and more sophisticated equipment,
like good quality CT, MRI, PET/CT etc. These have
already allowed clinicians to diagnose with much better
accuracy. In future we anticipate that with more
development in algorithms and computing power,
computer assisted diagnosis based storage and backup
infrastructure for reliably storing the studies will further
make life easy for all clinicians.
Traditionally, film served many purposes in the
organization of the conventional radiology department.
The "filmless" environment is now made possible by
PACS, has replaced traditional delivery mechanisms with
electronic ones which include features like auto routing,
perfecting, and manual-retrieval. The image records could
be made available on CDs/DVDs. The selection of the CD
writer device must also be carefully evaluated and
designed so as to be able to take on the workload.
Different sizes and configurations are available. Time
taken to burn CDs must be estimated and accordingly
clients must be given the collection times for reports.
There are a few people, or groups of them, who play
key roles in achieving successful PACS facility
installation - the radiology manager, the IT manager, the
PACS administrator and the Radiologists. They must be
involved in the selection and implementation process for
the PACS as early as possible and their inputs given due
credence. Circum-venting any of these persons could
create possibilities of resistance, dissatisfaction and
failure. Each party may have their own priorities, such as:
Will the PACS save or cost money? Will it add to my
workload? Will it help improve work quality and
efficiency? While it may not be possible to satisfy
everyone completely, the effort spent to involve these key
players upfront in the decision-making process can
increase the likelihood of success.
It is observed that more and more physicians and even
patients have started preferring the PACS systems to hard
copies. Turnaround time for modalities connected with
PACS is much faster in comparison to traditional films.
Further there is no easy way to keep hard copies of 64-slice
CT, PET/CT, 4D/5D etc and keeping them digitally
remains the only viable option. The future is the use and
integration of CPOE (Computerized Physician Order
Entry) to further enhance healthcare delivery systems.
The response for PACS in India? Quite good! In fact,
the market is getting very exciting. Most of the top league
hospitals are already using PACS while most other
progressive hospitals are exploring PACS. Earlier signi-
ficant high cost of ownership, due to high license fee and
hardware & storage costs were deterrents. However the

5. Apollo Medicine, Vol. 7, No. 3, September 2010 184
Review Article
spiraling prices of hardware & storage, combined with
reasonably priced solutions from some of the vendors has
removed that barrier. Today, hospitals of any size can
acquire highest quality PACS server and specialist
workstation at a price affordable to them.
In conclusion, PACS is the way to go considering
trends in healthcare progress in our scenario. Various IT
applications that a hospital uses can be categorized as PAS
(Patient Administration System), CAS (Clinical
Administration System), EMR (Electronic Medial
Records) and ERP (Enterprise Resource Planning). In
order to get complete view of a patient's EMR, integration
of complete radiological studies is needed, and, this is
maintained in PACS. This makes PACS an essential part
of continuity of patient care and significantly contributes
towards the best practices in patient management.
BIBLIOGRAPHY
1. Lee F Rogers: PACS Radiology in the digital world; AJR
Sep 2001.
2. Paul J Chang: Challenges and opportunities for
Radiology in the next millennium; Radiographics 2001,
July-August 1013-1014.
3. Imaging Business Journal PACS in India.

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