A Picture Archiving and Communication System (PACS) is a sophisticated computer network that allows radiological images and reports to be digitally stored, securely transmitted, and retrieved across clinical locations. It replaces the traditional system of storing film-based medical images. PACS provides simultaneous access to current and prior images for multiple physicians and radiologists, enables rapid transmission of patient information, and overcomes the limitations of film-based storage like loss of images and slow retrieval times. It integrates all radiology equipment, workstations, the digital image archive and the hospital information system.

1. PACS
By:
Dr. Shivam Batra

2. Picture: radiographic images
and radiology reports.
Archiving: the “electronic”
storage of the images
Communication: multiple
viewers of images and reports at
using workstations
System: the specialized
computer network that manages
the complete system

3. Film-based acquisition and archiving
(hard-copy film and document storage)
Digital acquisition and archiving
(soft-copy storage)
 Complex computer network has been created to
manage images.
 This network is called Picture Archiving and
Communication Systems (PACS).
 PACS is a sophisticated array of hardware and
software that can connect all modalities,
workstations, the image archive, and the medical
record information system into an integrated
system.
 For storage and distribution of images and
information when necessary.

4. WHY DO WE NEED PACS ?
 Simultaneous access to previous image data
 Simultaneous review by multiple physicians and
radiologists
 Rapid transfer of information
 Overcome the limitations of film-based systems

5.  Space
 Man power
 Cost
 Simultaneous access
 Inability for rapid retrieval
 Chances of losing
LIMITATIONS OF FILM BASED SYSTEM

6. 1. Acquisition 2. Network
3. Archive
4. Display/
Workstation
Image DatabaseRIS/ HIS
-CR
-DX
-CT
-MR
-US
-CRT
-LCD
Status of
Exams
Status of
Images
-database server/ image
manager
-Short term/ long term storage
- Workflow manager

7. SUBSYSTEMS AND COMPONENTS
 Image acquisition devices
 Data management and storage systems
 Transmission network
 Image display stations and devices to produce
hard-copy images.

9.  An archive server is the file room of the PACS.

10. THIS INCLUDES:
 patient demographics
 examinations the patient has had since the PACS
was installed
 information necessary for the PACS to be able to
find the images for those examinations, and to
direct copies of the images to local storage as
required

11. THE SERVER ALSO PERFORMS:
Routine scheduled tasks required for system
maintenance, i.e.
 Daily and/or weekly backups
 Pre-fetching of historical images for review
purposes
 “Flushing” of the online storage.

12. ALSO,
It allows the system administrator to carry out manual
tasks and system tuning as required, i.e.
 Management of user accounts
 Restoring discrepancies within the database, and
 Managing interfaces with external information
systems.

13. STORAGE/ DATA ARCHIVE
Archiving can be online, near-line or offline depending
on the availability of data.
 Hard drive is used for online storage and data in
online storage is readily available and it can be
accessed almost immediately.
 Tapes and optical media which are loaded
automatically by juke-box are called as near-line
storage.
 In offline storage data is loaded manually and the
loading time may vary.

14. STORAGE HARDWARE:
Mainly done by:
 Disk-based storage
 Tape storage
 NAS & SAN i.e. Network Attached Storage and
Storage area network

15. DISK BASED STORAGE
It comprises of 3 media:
 RAID i.e. Redundant Array of Inexpensive Disks
 DVD i.e. Digital versatile disks
 MOD i.e. Magneto optical disks

16.  RAID is exclusively used for online storage
 Instead of using a single large hard disk to provide
the required storage capacity, it uses a number of
smaller, cheaper disks to provide, in total, the same
storage capacity by using data striping and data
mirroring.

17. BESIDES,
 DVD has a storage capacity of 4.7 GB
 MOD has a storage capacity of 9.1 GB

18. TAPE STORAGE
There are many tape formats used for near-line and
offline storage:
 Advanced intelligent tape: Can store 50 to 100
GB, with a data transfer rate of 12 MB/ sec.
 Jukebox

20.  It is the interactive component of PACS where the
radiologists interpret and generate a report.
 A typical workstation comprises:
• Display monitors
• Computer
• Local storage which is connected by network
cables

21. DISPLAY MONITERS

22.  Image display in PACS is a flexible and
dynamic process whereby radiologists
directly interact with the soft-copy image,
which is displayed on a computer
workstation.
 The hardware component of a display
system for PACS is composed of a display
device and a display controller. The
specifications given for a system are valid
only for that particular combination of device
and controller.

23. Two different monitor display technologies
1. Cathode ray tube (CRT)
2. Liquid crystal display (LCD)

24. DISPLAY MONITORS
Two types:
 Cathode ray tube (CRT) monitors: utilize older
technology which has been used in televisions for
decades and they are relatively cheaper.
 Liquid crystal display (LCD): is a newer
technology which is relatively expensive.

25. CRT VS LCD
Advantages of LCD monitors are:
 a. Thin and light weight
 b. Less power consumption
 c. Brightness of display
 d. Flat surface
 e. Aspect ratio is maintained.
Disadvantage of LCD monitor:
 It has narrow viewing angle than CRT monitors.

26. Advantages
 Better color clarity and depth
 High refresh rates
 High contrast
 More responsive
 Less ghosting and blurring
 Flexible, with multiple resolutions
 Image quality superior to that with LCD/plasma
 Lower cost than LCD or plasma
Advantages and limitations of cathode ray tube monitors

27. Limitations
 Bulky, heavy, and uses space on desk
 Constant refreshing can result in headache
 Operates at very high voltage; overheats system
 Health hazard due to electromagnetic field
emission
 Limited brightness level
 Decreased brightness and sharpness at edges
 Phosphor efficiency fades with time
 Phosphor burn artifacts, with ‘ghost negative
images
 Impedance mismatch artifacts, with ‘bleeding’ of
white into black and vice versa at black /white
interfaces

28. LAN WAN

29.  Transmits data from one place to another.
 Types:
• LAN i.e. Local area network: connections
between computers with in a hospital
• WAN i.e. Wide area network: When multiple
LANs are connected
• VPN i.e. Virtual private network: commonly used
nowadays to view the images from anywhere in the
world using the internet infrastructure.

30. SYSTEM ARCHITECTURE
 Consists of acquisition devices, storage, display
workstations, and an image management system.
 Three common PACS architecture:
 Client/Server-based Systems
 Distributed Systems
 Web-based Systems aka Cloud computing (used in
Teleradiology)

31. Internet-based computing that enables the sharing of
resources, software and information to computers and
other devices on-demand.

35. communication standard
for sharing medical
images
communication standard
for medical information.

36. To facilitate free flow of information across modalities
and networks in health care industry standards have
been developed.
 Health Level 7 (HL7) is the industry standard for
the transmission of textual information
 Digital imaging and communications in
medicine (DICOM) is the industry standard for the
image data and communication protocols

37. Integration with other information systems
& display of relevant data on desktop are
critical for success of PACS.
HIS
hospital
billing
to
inpatient
ordering
system
RIS
patient
scheduling
to
radiologist’s
dictated and
transcribed
report

38. RADIOLOGY INFORMATION SYSTEM (RIS)
 In the modern digital radiology department RIS
forms the backbone which controls almost all
aspects of radiology workflow.
 It drives the workflow and transfer of information
across the department.
 It deals with nonimage text based computing
functions such as scheduling of an appointment,
generation of worklist, order tracking, billing and
reporting.

39. Exam
Order
Exam
Scheduled
RIS Patient Exam
Is Performed
Modality Worklist
Demographics
Downloaded
Database
server
/Archive
Order
Event
Prefetch Exams
From Storage
Images
transferred
PACS Worklist
Updated
Images /
Prior Reports
Exam
Transcribed
Report
Verified
Final report
available
Exam
Read
Dictated
status
Preliminary status
Web
distribution
to referring
physicians

40.  Rapid (electronic) transfer of images within the
hospital (e.g., clinics, operating rooms)
 Simultaneous viewing of images at multiple locations
 Increase in efficiency of reporting exams with soft-
copy images
Offers the basic functions of
 Gray shade level adjustments and customized
windows
 Zooming and panning
 Measurements (length, area)
 Conversion to JPEG formats in single click
 AVI conversion and encoded algorithms to convert to
mp4, which can be sent to emails and viewing on
smart phones.
 Can be integrated to HIS (flat file)
 Generate monthly reports

41. Fast delivery, no
lost images,
reliable quality.
Manipulation of
images,
comparison,
Teleradiology,
learning
Instant access to
images, better
quality consultation
Cost savings, less
staff, space
saving, less
chemical usage
Saves time, Less
Radiation

42.  Having A PACS solution definitely allows for images to
be viewed across network from where ever you are in
a systematic manner.
 However, just having a PACS solution, if seen critically
cannot be the only solution to ensure a quick TAT for
reporting.
 Having customized templates for positive and negative
studies integrated with PACS and options of recording
/transcribing…Voice Recognition Systems…..are some
methods which can make PACS more effective with
reference to TAT.

43. Accessibility
Producti
vity
Cost &
Time
Effective
Digital Storage
Faster Retrieval
Facilitate Time
Management
for Radiologists
Patient
Satisfaction
View Cases
from
anywhere