PACS introduction

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PACS introduction

• Facilitator
• Edward Wong

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What is the role of PACS Administrator?
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PACS Administrators roles

• Implementing a PACS
• System Maintenance
• Image and Information Management
• For a 200,000 exams/year institution, 2-8 full
  time PACS Administrator is available!

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PACS Administrators roles

• Implementing a PACS
• - Financial and workflow study
• - Request for Proposal and Tender drafting
• - Workflow modification including job
  reallocation and resource relocation
• - Training and Operation Manuals
• - Acceptance of system
• System Maintenance
• Image and Information Management

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PACS Administrators roles

• Implementing a PACS
• System Maintenance
• - Contingency plan
• - Incompatibility handling
• - First line support and problems escalating
• - System security and Performance monitoring
• Image and Information Management

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PACS Administrators roles

• Implementing a PACS
• System Maintenance
• Image and Information Management
• - Maintain high Image Quality
• - Data Integrity
• - Quality Assurance program
• - TeleRadiography
• - Anytime Available Storage Management

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What is PACS ?

• P Picture, Images Reports
• A Archive, Online, Near line, Offline
• C Communication, Networking, Transfer Protocols
• S System, Components Architecture
• PACS for storage and distribution of images and
  information when necessary

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PACS Small or Large
Web Server Distribution
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Scale of PACS

• No. of Beds in Hospital/ Exams per year
• No. of Modalities
• No. of Switches
• Considerations
• System connectivity, expandability, reliability
  and cost-effectiveness

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Types of images

• 1D, 2D, 3D, 4D
• Different DICOM Modality type Cardiac / PET / 4D
  U/S..
• Image size Resolution and bit depth
• Image quality Bit Depth and resolution
• Color / Monochromatic
• Exam. Size image size x no. of images
• Structured Reports
• New DICOM IOD
• Endoscopic Microscopic images / ECGs /
  Security Profiles..

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1D, 2D, 3D, 4D, fusion
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1D, 2D, 3D, 4D, fusion
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Image Resolution/ Bit depth
U/S DF CR
CR Mammogram
256 x 256 8 bit 65 KBytes
1k x 1k 10 bit 1.25 MByte
2k x 2.5k 12 bit 7.5 MByte
4k x 5k 12 bit 30 MByte
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Properties of image

• Bit depth
• Grayscale or color
• Resolution in pixel
• Example image size of mammogram 4k x 5k x 12
  bit 30 MB

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PACS Architecture
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PACS Central Architecture
DICOM Modality
Diagnostic Workstations (DICOM)
Clinical Workstations (DICOM)
Image Server (RAID)
Gateway or Frame Grabber
Diagnostic Workstation
Non-DICOM Modality
Film Digitizer
Web Server
Data Base Server
CR/ DR QA Workstation
Archive
Computed Radiography or DR
RIS
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Central Architecture

• Image Server and Database Manager is the HEART
• Any image, any where, any time
• Unique central copy
• Easy update of data
• Requires high performance servers
• Potential single point of failure at server
• Bandwidth demanding

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PACS Distributed Architecture
DICOM Modality
Gateway or Frame Grabber
Diagnostic Workstations (DICOM)
Clinical Workstations (DICOM)
Web Server
Non-DICOM Modality
Diagnostic Workstation
CR QA Workstation
Film Digitizer
Data Base Server
Archive
Computed Radiography
RIS
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Distributed Architecture

• Exams are routed from modality to selected
  workstations
• Complex routing algorithms based on department /
  user preference
• Difficult to support concurrent review of images
• Less destructive for failure at database server

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Components of PACS

• HIS/ RIS
• Broker
• ePR gateway
• Database Server
• Image Server (RAID)
• Long Term/ Near line Archive
• Networks
• Digitizer

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Components of PACS

• Acquisition Gateways
• Non-DICOM modality gateway
• DICOM Print Server
• Media Server
• Reporting Server
• Monitor QC Server
• Web Server
• Workstations

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PACS layout 1
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PACS layout 2
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PACS layout 3
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Tuen Mun Hospital PACS System - Ambulatory Care
Center (phase 1)
Image Acquisition Modalities in ACC
ACC Ortho Dept
RW Film Digitizer
PathSpeed SP CR
PathSpeed MP CR
1C PathSpeed Review Stations
Main Block Radiology Department
Hospital RIS Network
Server Rm Network Switch Closet
CT Network
MR Network
RT Network
1 GBit Fiber Link
Kodak Laser Printer 1
Kodak Laser Printer 2
600m / 12 Core Gbit Fiber Link
KELP 2180
DryView 8700
Layer 3 Sw Layer 2 Sw
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PACS layout 4
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PACS Components
ePR gateway
Enterprise Archive
DICOM Modality
Diagnostic Workstations (DICOM)
Through Acq. gateway
W/S QA Server
Clinical Workstations (DICOM)
Image Server (RAID)
Gateway or Frame Grabber
Diagnostic Workstation
Non-DICOM Modality
Film Digitizer
Web Server
Data Base Server
CR/ DR QA Workstation
LTS Archive SAN/NAS
Computed Radiography or DR
Media Server
Broker for RIS/HIS
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Acquisition (DICOM) Gateway
HIS/RIS Interface (Broker)
DG
RIS
PCs
W/S
Film Digitizer
CR QA
Frame Grabber
RF
CR
US
XRAY
CT
MR
NM
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Role of Acquisition gateway

• Compression/ decompression and security
• Check the images for integrity
• Convert to PACS format (header, byte-order,
  matrix size)
• Queue for images (priority) to database server
  (background)
• Share the workload and no point of failure for
  multiple Acquisition gateway

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Database Server and Image Server
Database Server
HIS/RIS Interface (Broker)
DG
RIS
PCs
W/S
Film Digitizer
CR QA
Frame Grabber
RF
CR
US
XRAY
CT
MR
NM
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Database Server (PACS controller)

• The Heart of the system
• Integration cross point between HIS/RIS and PACS
  (status update)
• Create and manages patient folders
• Manage reading worklists and user profiles
• Manage data transfer within the system
• Support data mining and teaching folders

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Image Server (RAID)

• Online (rapid access) exam storage and
  distribution device
• Support simultaneous exam input and output
  transfer operations
• Up to Three months of storage capacity
• Scalable capacity

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What is RAID

• Redundant Array of Independent Disks
• Bandwidth equal to sum of disk transfer rates
• Highest speed disk storage available

Hot Swap
2 MB/s
1
2
3
4
5
6
16 MB/s
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8
Image
Parity
Disk Array
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RAID 5 configuration

• If disk fails, disk can be rebuilt- fault
  tolerant
• High data transfer rate for read, write slower
• Min. 3 disks to start
• Array capacity is N-1

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Bandwidth
Bandwidth is a measure of the information (data)
carrying capacity of a network 10/100/1000 MB/sec
Information Flow
Data Pipe (Network)
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Network Bottleneck
The bandwidth of an information delivery system
is limited to the bandwidth of the slowest
component in the system
Network Bottleneck
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Data Compression
Data compression reduces the information rate a
network must support
Uncompressed Data
Compressed Data
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Lossless Image Compression
I - D 0
C
D
I

• Decompressed image is identical to original image
• JPEG lossless compression
• Average compression of 21 for x-ray images

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JPEG 2000 Compression

• Selected parts of the image can be defined as
  Regions of Interest, they can then be delivered
  before other parts of the image, or losslessly,
  whilst other parts of the image that are less
  critical use normal lossy compression
• JPEG 2000 codestream can be ordered to deliver
  images of lower resolution before the full image
  can be transmitted
• Motion JPEG 2000 does not have any form of
  extrapolation (and hence potential distortion) in
  the time domain.  Each frame is a separate JPEG
  2000 coded image

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JPEG 2000 images
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Storage Device (Long Term)
Database Server
MOD
DLT
HIS/RIS Interface (Broker)
DG
RIS
PCs
W/S
Film Digitizer
CR QA
Frame Grabber
RF
CR
US
XRAY
CT
MR
NM
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Types of storage media
Media DVD MOD WORM DLT 9840 AIT2
GB 3.8 5.2 35 20 50
Cost Less Expen. Expen. Expen. Cheap Most Expen.
Load Assess Very fast Very fast 113 sec 15 sec 45 sec
Max. T rate MB/s 5 5.1 5 10 6
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Long Term Archive

• Used to store digital data for longer periods of
  time
• Storage ranges from 100 MB to 10 TB
• Optical disk most common media
• - 5 1/4 MOD
• - 2.6 GB and 5.2 GB Capacity
• DLT used for longer term storage and redundancy
• ISP module

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Storage Device (Near line)
Database Server
SAN/NAS
MOD
DLT
HIS/RIS Interface (Broker)
DG
RIS
PCs
W/S
Film Digitizer
CR QA
Frame Grabber
RF
CR
US
XRAY
CT
MR
NM
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Storage Area Network

• SAN is a high-speed sub-network of shared storage
  devices
• Contains storage device (disk) for storing data
• SAN's architecture works in a way that makes all
  storage devices available to all servers
• Use of Fiber Channel
• High scalability for additional storage and
  redundant networks

PCs
Storage devices
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Network Area Storage

• NAS is a class of dedicated hard disk-based
  storage devices which provide LAN users with
  additional disk storage through a standard
  network connection
• In most cases, a NAS device (or NAS server)
  receives an IP address, connects to the LAN
  through an Ethernet cable, and resides on the LAN
  as an independent network device
• Users are not demanding the server's processing
  time for mundane storage tasks -- often improving
  the performance of local application servers
• NAS systems also include some onboard memory
  (RAM) to cache network data to or from the disks

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SAN Vs NAS

• Difference between NAS and SAN is subtle
• NAS devices are big, single purpose storage
  appliances that you plug into network
• NAS sits between your application server and your
  file system
• As perform only 1 task, can serve files very fast
• NAS is network-centric
• SAN is a defined architecture that sits between
  your file system and your underlying physical
  storage
• SAN is data-centric

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Display
HIS/RIS Interface (Broker)
Database Server
MOD
DLT
Diagnostic W/S
Dedicate W/S
SAN/NAS
DG
RIS
PCs
W/S
Film Digitizer
CR QA
Frame Grabber
RF
CR
US
XRAY
CT
MR
NM
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Workstations

• Four Primary Categories
• - Advanced Analysis Used by specialists for
  advanced diagnosis - 3D, volume rendering
• Diagnostic For primary diagnosis located in
  reading rooms high-end 2K monitors
• Clinical Used by clinicians and staff to
  consult ICU / ER applications less costly than
  diagnostic 1K monitors
• At Home Review low-end PC based
  cost-effective review application lossy
  compressed for faster transmit

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Standalone Vs direct PACS w/s
Standalone Workstation Direct PACS Client Workstation
Hard Disk Storage Yes, varies Minimal
Query PACS number All PACS system (CT, ACC, Angio.) Single PACS system (ACC PACS)
Retrieval mechanism DICOM Q/R and association made with different vendors Direct attached, same vendor
Retrieval time Slower Faster
Diagnostic value Depends on Monitor Grade and Modules like MPR, 3D etc Depends on Monitor Grade and Modules like MPR, 3D etc
Suggested usage for meeting/museum purpose for single modality image reviewing and reporting like Radworks in U/S Rm Direct PACS workstation for reporting
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Web distribution

• High availability, low cost
• Reports / select images to referring physician
  desktop
• Point of integration with electronic patient
  record
• Lossy compression for performance
• Potential for TeleRadiology
• Security issues to be resolved

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RIS, HIS, ePR and PACS integration
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Broker HIS/RIS and PACS interface
HIS/RIS Interface (Broker)
DG
RIS
PCs
W/S
Film Digitizer
CR QA
Frame Grabber
RF
CR
US
XRAY
CT
MR
NM
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Hospital Information System

• Support clinical and medical patient care
  activities in the hospital
• Administer the hospitals daily business
  transactions like finance, payroll etc
• Evaluate hospital performances and costs and make
  long-term forecast

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Clinical System in HA, HK

• Patient Administration
• In-Patient and Out-Patient Administration System
• Accident Emergency Information System
• Medical Record Abstract System
• Medical Record Tracking System
• Clinical Support
• Laboratory Information System
• Radiology Information System
• Pharmacy Management System
• Dietetics Catering Management System
• Clinical Management
• Clinical Management System (In-Patient) Discharge
  Summary
• Clinical Management System (Out-Patient)
• Electronic Patient Records
• Clinical Data Analysis and Reporting System

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Non-Clinical System in HA

• Human Resources and Payroll Systems
• Hospital Based Financial System
• Materials Management System
• Patient Billing and Revenue Collection System
• Executive Information System
• Code 9 and view codes

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Radiology Information Systems

• Similar to HIS but of smaller scale
• Interfaces to PACS based on HL7
• Department administrative management
• - Scheduling and Film tracking
• - Resource management and reporting
• - Monitor patient status
• Link to Hospital Information System (HIS)
• - Billing and Master Record
• Link to Clinical Management System (CMS)
• - Prefetch for Clinical visit
• - ePR integration

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Exam Order
Exam Scheduled
RIS workflow
RIS
Modality Worklist Demographics Downloaded
Patient Exam Is Performed
Images copied on web-server
Images transferred in STS
Order Event
Database server /Archive
Exam Read
PACS Worklist Updated
Prefetch Exams From Storage
Images / Prior Reports
Dictated status
Image migration STS to LTA
Final report available
Report Verified
Exam Transcribed
Preliminary status
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Broker service
DR
HA HIS
CR
ADT
Mitra PACS Broker interface
HA RIS
Appt., X-ray request
HA CMS
Clinical visit
US
DF
Database server
Modalities Get WORKLIST Get REPORT, Get INFO
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Broker service

• A restricted access account will be created at
  Sybase that gives limited authority for the DICOM
  Broker solely for the purpose of the interfaces
• In general, for data flow from RIS to the Broker,
  the RIS write the supported events to the table,
  and the Broker polls against the events table and
  calls the associated stored procedures for the
  conversion to DICOM messages

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Broker service

• Broker main function
• - Worklist generation
• - Reports storage

Registration Post exam data capture (RIS)
Acc generation call broker for update
Need SOME time!!
Broker poll RIS event table and convert to DICOM
info
Modalities query Broker for worklist update
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ePR Architecture

• Selected images from individual hospitals PACS
  are sent
• make use of the ePR record indexing and browsing
  capabilities to read the radiology images through
  CMS workstations

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Data Flow Diagram
RIS
ePR
HA system
Appointment Attendance Exam records Reports
(15mins)
CMS
RIS operational data
ePR
Web Server
PACS
Attendance Exam workload units (daily)
RIS statistical data
Data warehouse
Non clinical system
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Characteristics of ePR

• Near instant image review
• Web distribution can be within hospital, to other
  hospitals or even private clinics
• TeleRadiography possible
• Update of patient information
• Lossy Vs lossless
• Broken pathway
• 15 minutes time lag

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Guidelines for HIS, RIS, PACS interface

• Each system remain unchanged in its configuration
  and function, only data are shared
• Identify the subset data to be shared and set up
  access rights/ authorization
• Convert the subset data to HL7 standard
• Define transfer protocol (TCP/IP or DICOM)

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Typical patient and data flow

• Admission Patient registration, notify HIS (HL7)
• Order entry/Arrival Schedule exam and notify RIS
• Broker notified and PACS database server updated
  (prefetch)
• DICOM worklist to modality
• Exam completed data to DICOM gateway (MPPS)
• Information/images to database/image server
  through gateway (DICOM store)
• Images stored in PACS archive
• Images to workstations from PACS archive
• Dictation, transcription etc workstation to
  RIS/PACS
• RIS reporting and PACS updated for reports
• Transfer HIS/RIS to PACS, images to other PACS
• Discharge HIS/RIS to PACS, images rub out

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http//www.pacs.hk

• Thanks!