PACS Mini Refresher Picture Systems: Robert
Archiving and An Overview1
H. Choplin,
Jobannes C. Douglas
Organizational
MD
fail
needs
the capacity
of radiology
acquired
departments
larger.
With
of film-based
departments
with
small
become
chiving and communication tempt to provide economical images
enable
that
as departments
technology,
imaging ing
II, MBA
techniques
often
Communication
MD
M. Boebme Maynard,
ciently
Course
has
systems storage,
multiple
to function the
systems
decreased.
(PACS) rapid
recent
effi-
growth
to meet
in
the increas-
Electronic
picture
an-
have been developed in an atretrieval of images, access to
modalities,
and
simultaneous
access
at multi-
pie 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
network),
image
mission
network
system
that
storage
devices
(which
serves
controls (both local
The
maintaining
goals or
management
lenges a large
facing number
locations;
areas),
are
to improve
on
the
archives),
display
image monitors, images (currently,
diagnostic
of medical
medicine today. of nadiologic
as a result,
neous
access
dition,
trans-
stations
(which
and a user interface), a multiformat or laser
operational
efficiency
while
ability.
may
may
be needed
physicians
caning
for
centers
increase
HIS
information
system
Index
terms:
Images,
=
in size,
hospital
display
information
. Images.
system,
transmission
be
a patient
illnesses
of the
inadvertently
for may
increase
PACS
=
#{149} Picture
picture
to review
archiving
and
and
Simulta-
interpretation.
in complexity,
archiving
chal-
duplicated.
accurate
want
greatest
problems may require at physically separate
the
and
communication
communication
In ad-
images.
the
system.
system
As
demand
RIS
=
radi-
(PACS)
1992; 12:127-129
RadloGraphics the
Department
27157-1088. RSNA,
preexisting
is one
complex medical may be performed
studies
ology
reprint
information
with which
images
Abbreviations:
From
imaging
Patients studies,
to radiologic
multiple
medical
C
of information long-term
INTRODUCTION
U
Timely
I
of PACS
improving
flow and
on wide
include a computer, text monitor, and devices to produce hard-copy camera).
the short-
From requests
of Radiology, the
1991
RSNA
Bowman scientific
Gray assembly.
Schol
of Medicine,
Received
September
Medical 23.
Center 1991;
Blvd. accepted
Winston-Salem, September
NC 27. Address
to R.H.C.
1992
127
for rapid cordingly,
logic
transfer of information increases the capacity of film-based radiosystems to meet these demands de-
creases. Films are often unavailable and film storage costs are relatively Systems
putens
designed
and
monitors
have
10-12
to store
display
years.
them
been
communication
vice.
the
archiving
systems
(PACS)
past
and
attempt
to
overcome the limitations of film-based systems by providing economical storage, rapid retrieval of individual images, access to images acquired with multiple modalities, and simultaneous access to the same image at multiple sites. However, acceptance of this new technology has been limited by high capital costs, limited spatial resolution of the display
monitors,
limited
digitization
phy,
spatial
modalities
slow
image
for
display
resolution
of
projection
with
and and
(ie,
high
nec-
with
is based on its size and digital input devices.
the
the
mix
of
has
whereas
high
capacity
and
the
long-term
low
utilization.
Transmission
in film-based
.
into
Data for images, text, and system commands are transmitted over networks serving local or wide areas. The network medium could be a twisted-pain wire, coaxial cable, on fibenoptic cable. A variety of network topologies (eg,
segments
of larger
radiology
departments
(1-4). search velop
The intensity and breadth ofthe nebeing undertaken worldwide to dethese systems are exemplified by the
many
symposia
In this concepts briefly
dedicated
article,
we
needed
to this
introduce
topic
the
to understand
describe
constitute
the
such
main
star)
(5,6).
primary
a PACS
components
and that
digital
modality format
that
creates
(computed
the
from
image
a transmission
stations,
and
an
tomography,
ultra-
network,
devices
image
to produce
display
a
then
stations
lected
Image
Acquisition
An image gateway
acquisition to the PACS
converter
digital
information
RadioGrapbic.s
or
its own
advan-
used
to create
different
appropriate
for the
levels equipment
task
a series
of work-
of sophistication may
be
se-
at hand.
Modules device is an electronic and may be an analog-todevice from
U
be with
so that
digital
with
available with film systems has not yet been constructed. In fact, the cost of creating such a station would be formidable. To help minimize the potential costs, studies have been undertaken to determine the minimal spatial and contrast resolution necessary to perform a variety of imaging tasks. This information may
hand-copy
images. .
each
. Image Display Stations Image display stations are the principal area of physician interface with a PACS. A display station includes a computer with local stunage, a text monitor, a variable number of image monitors, and a user interface. A display station that can duplicate the full range of tasks, speed of display, and spatial resolution
in a
sonography, magnetic resonance imaging, nuclear medicine, on computed radiography), or from an analog image that has been processed by a digitizer. In either instance, the signal could come from local equipment or from distant equipment via a telenadiology network. A PACS includes several subsystems and components: image acquisition devices, data management system, data storage devices,
available,
a system.
PICTURE ARCHIVING AND COMMUNICATION SYSTEMS The input to these systems may come imaging
are
Network
tages and disadvantages. In addition, several communication protocols (eg, transmission control protocol/internet protocol [TCP/IP]) exist for managing the information on the network. These protocols provide instructions on how data will be moved on the network.
U
U
varies
that
systems), and the need for system redundancy to provide backup in case of component failure. Most PACS in current use are prototypes intended for research, although recently some have been incorporated
128
modules
to function
utilization),
archive
radiogra-
(compared
ofacquisition
a PACS
. Data Management System The data management system is a specialized computer that controls the network, image storage devices, and image acquisition devices in order to maintain orderly traffic flow in the system. This computer manages patient information and images as well as the associated reports. The data management system must provide shortand long-term archiving capabilities. Usually, the short-term archive employs magnetic media, and the long-term archive employs optical media. The short-term anchive has low capacity but is frequently used
in com-
oven
picture
number
for
system analog
or lost, high.
images
The
essary
on high-resolution
developed
These
ac-
that
passes
a digital
Choplin
imaging
eta!
along de-
. Hard-Copy Although the play
with
also
be
Devices major
a PACS made
for
mode is electronic, creating
of storage
and
provision a conventional
Volume
dismust im-
12
Number
1
Icu INTERPRETATION EGOW Xl
Topology system.
three
of the
EGDW units, x2
PACSRIS-HIS
enhanced
= =
two
network
graphics
units,
xl
=
at our
display one unit.
age on x-ray film. Multiformat cameras cameras are currently the most common of meeting this demand. U
INTERFACES
To function system
must
TO OTHER
properly,
the
interface
with
institution.
workstation,
on laser way
patient
care
management systems. These include but need not be limited to a radiology information system (IllS) and a hospital information system (HIS) (Figure). The goals of interfacing the PACS to an RIS and an HIS are to maintain data integrity across the global system and to optimize the performance of each component system
by
fon each. nies,
using
The
reporting
only
the
1115 provides of results,
specific
data
basic and
tributes patient care the medical center. U
information
2.
3.
needed
patient
histo-
collection
data for department management. manages the demographic standards
U
1.
management
other
ing,
of
The
HIS and dis-
4.
throughout
January
on improving
data
x4=
of a PACS
units,
x3
is its ability
efficiency high
management
four
while
diagnostic
=
to im-
maintainability.
REFERENCES Templeton AW, Dwyer SJ III,JohnsonJA, et al. Implementation of an on-line and long-term digital management system. RadioGraphics 1985; 5: 121-138. Arenson RI, Seshadri SB, Kundel HL, et al. Clinical evaluation ofa medical image management system for chest images. AJR 1988; 150: 55-59. Taira RK, Mankovich NJ, Boechat MI, Kangerloo H, Huang HK. Design and implementation of a picture archiving and communication system for pediatric radiology. AJR 1988; 150: 1 117-1121. Choplin RH, Maynard CD, BoehmeJM, et al. Conversion to filmless radiology: getting from here to there (abstr). Radiology 1988; 169(P): 402.
Dwyer SJ III, Jost RG, eds. Medical IV: PACS system design and evaluation. ceedings of the International Society cal Engineering, vol 1234. Belhingham, Society of Photo-Optical Instrumentation neers, 1990.
6.
Lemke HU, Rhodes Computer assisted ofthe International
SUMMARY
1992
promise
operational
of the
unit,
5.
The practice
of radiology is a complex system that includes generation of images with multiplc modalities, image display, image interpnetation and reporting, and image file management. Organizational systems that enable efficient functioning in small departments often fail as departments grow larger. Although the development of systems to meet increasingly complex needs will be challeng-
the
prove ing
SYSTEMS
image
Note the star topology JUl = intensive care
lin:
Springer-Verlag,
Choplin
ML, Jaffee radiology. Symposium
imaging Profor ()ptiWash: Engi-
CC, et al, eds. In: Proceedings
(CAR ‘87).
Ber-
1987.
et a!
U
RadioGrapbics
U
129