Integrating a PACS - Interfacing Computers,

Doctors and IT Personnel

Robert E. ZimmermanJoint Program in Nuclear Medicine

Harvard Medical School

Boston MA

PACS - How to Choose

Integrating Cameras

Each camera has to be included in the mini-PACS (ideally)– analog cameras– older “digital” cameras– Newer digital cameras

Not Rocket Science!Not much computer science either

• NM mini-PACS is (for the most part) standard, everyday computer technology except for...– Format of camera/computer to

archive/database– Reverse flow of data to

camera/computer–Medical workstation considerations

Let’s examine some of the issues

camerasworkstations

Archive &

database

camerasworkstations

Archive &

database

DICOM?

Other?

?

3 cases

1. Analog camera

2. Existing NM computer

3. New camera/computer purchase

workstations

Archive &

database

Example 1

analog camera

NM computer w/ ADC

$15-25K

DICOM $other

workstations

Archive &

database

Example 2

existing NM computer

NM computer w/ ADC

$0

other

workstations

Archive &

database

Example 3

new camera and computer

Integrated camera/computer

~$500k

DICOM $other

Archive and database

Should it be DICOM?– DICOM - v. expensive - still– But it is the future for image transfers

between modalities and vendors– It will integrate to Radiology PACS–Will require DICOM workstations

• v. expensive

• no to poor color support

Archive and database - 2

Could be a conventional database with a DICOM export facility

– export could be manual or automatic based on some rules

camerasworkstations

Archive &

database

Dicom?

Other?

computer

computer

computer

computer

computer

computer

DICOM $other

Do you want your data back?

Archive back to camera/computer for re-processing?– big problem– little support by major companies

• unless single vendor

– Once it is DICOM no more processing• at present

• exceptions at this meeting?

IT Personnel

Network infrastructure

HIS data

RIS data

May need separate workstation or window for this data

How to interface to the radiology PACS?

DICOM

DICOM

DICOM

Archive/database must have DICOM export feature

Some examples

1. A (nearly) single vendor situation.

2. A multivendor situation

Single vendor

All computers on the cameras come from same vendor

–maybe a costly but possible solution

Siemens cameras

workstations

Archive &

database

computer

computer

computer

computer

ICONs

ICONs + MedView

Mac server and std Mac hardware

Single vendor example

Discussion

How do you add another vendor?– E.g. Siemens ECAT

Solution– Separate but equal mini-PACS using

Sun hardware and ECAT software

Poor integration

Duplication– but it works well

Multivendor Computers on the cameras come

from different vendors

– problems in understanding the different proprietary file formats

– Interfile and DICOM are not full solutions

– Reversibility issues

DICOM

• A complex messaging protocol that includes file formats of various types

• DICOM is specified for each modality, including nuclear medicine.

• It is clumsy, costs a lot and is generally unnecessary

• Except when talking to a “big” PACS

Network Protocol

LLC

ISO NETWORK

ISO TRANSPORT

ISO SESSION KERNEL

ISO PRESENTATION

ISO Association Control Service Element (ACSE)

TCP

IP

DICOM Upper layer

protocol for TCP/IP

Session /

Transport / Network

(STN)

Data Link

Physical (50-pin) Ethernet, FDDI, ISDN, etc.

DICOM Application Entity

Medical Imaging Application

ISO Upper Layer Service boundary

Point-to-point Network Environment

PennState College of Medicine, Department of Radiologyhttp://www.xray.hmc.psu.edu/dicom/basicinfo.html

Interfile

• Interfile is a simple definition of a file format

• Useful for exchanging files with others

• No definition for gated files

• Consists of a descriptive header followed by raster format image file

• Two flavors: 1 file or 2 files

Multivendor-2 Format issues are not solved with

Interfile and DICOM.

– Neither is suitable as a “working” format– No color– No gated– not reversible– vendor differences

Cameras/computersworkstations

Archive &

database

computer

computer

computer

computer

computer

computer

A

B

C

D

E

F

Wintel + proprietary conversion software

Discussion

• Maximum flexibility

• Keep full options for new camera purchase

• Requires close cooperation between miniPACS vendor and NM clinic

• Increased complexity

Hidden Costs

• DICOM

• Your own engineer/physicist/computer programmer/system manager may be required

Acceptance testing

Camera to archive and back again

Archive to workstation

Workstation image quality e.g. SMPTE pattern

Workstation Issues

• Monitor Brightness/contrast

• Work area (ergonomics)

• Room – layout– illumination

• Periodic test of resolution, brightness, contrast

• optical transfer function (gray level mapping)

Workstation Issues -2

• Color?

• DICOM workstations and DICOM implementations do not have good color support

• Cine support

Some PACS vendors for NM

Marconi NUMA

Sudbury Systems Segami

Siemens Soft medical

ADAC SMV

MedImage

Apple Microsoft

Sun HP