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