DICOM General Purpose Worklist

The next major political battle in PACS Dr David Harvey

Why a DICOM Talk today ?

   DICOM General Purpose worklist is to reporting workstations what basic DICOM is to a CT Scanner You wouldn’t (I hope!) since 1995 buy a CT without checking the DICOM conformance You shouldn’t buy a reporting station (or PACS) in 2004 without doing the same

“Traditional” DICOM Queries

  Concerned with “static” data, which once generated is never altered.

 Images  RT plans etc.

Provides excellent methods for creating, storing, querying and retrieving such data,

if your starting point is a particular patient or study

Why original DICOM Queries are not suitable for workstations   No information or reporting status (unreported / reported / in progress) No way of querying for “things to do”  If patient IDs etc. are entered by hand, then there is a delay while images are actually retrieved.

Radiologists need a “NEXT” button

Key Features of GP Worklist Provides:  A

vendor independent

method of interfacing efficient reporting stations to a PACS  A mechanism to simulate the “reporting pile” (but in multiple places simultaneously)    A Locking mechanism to prevent accidental double reporting Wide range of query and priority fields to support chosen working practices.

Sufficient information to allow images to be pre-fetched.

Why Have a DICOM Interface?

   Is the best RIS/PACS supplier also the best workstation supplier?

Is the best workstation supplier also the best RIS/PACS supplier Or do you compromise?

Hot it works (the technical bit)

    Modelled on the existing modality worklist (MWL) and modality performed procedure step (MPPS) services Workstation first queries for items of a requested type Then it selects and locks an item Then marks it compeleted

MWL/MPPS SCU (Client) List of those available Lock (In Progress) Lock OK Mark Complete OK MWL/MPPS SCP (Server)

Worklist Data Source

 Exactly the same options as used by proprietary systems:  RIS   PACS Broker

Vendors have no technical excuses

   Data sources already exist (used for their proprietary systems) DICOM mechanisms already exist (used for MWL/MPPS) So where is it ?

Can I use it Now?

     At present,

NO

– because: It has only been in DICOM for 3 years (short time by development scales) Like all such protocols, it requires support from both SCP (server/PACS) and SCU (client/workstation) PACS suppliers don’t like it’s potential to eat into the very lucrative proprietary workstation market Only a few independent workstations support it yet Users haven’t yet learnt about it and demanded it!

Will it become available?

Perhaps ?

  Negative Features   Not all DICOM features become adopted widely Arguments from major PACS vendors:  Responsibility, Reliability etc.

  Positive Features   Adoption into IHE will push implementation by vendors Some smaller vendors are already using it  User ignorance May become an expensive retrofit option Like original DICOM, a few knowledgeable users may be sufficient to push the market

But won’t the national Program make this obsolete?

   Life of your RIS ~7-10 yrs Life of Government Initiatives ~2-4 yrs    Trusts 4ys (then merged) Information for Health – 3 yrs NPfIT – 3 yrs ?

You will still be using your system long after the LSP has lost interest or gone bankrupt!

Conclusions

 In 1994, you could buy a CT scanner which worked well with it’s own expensive secondary console, but if you wanted flexibility and choice for the future, you needed to insist on DICOM C-STORE  In 2004, you can buy a PACS which works well with it’s own expensive tied reporting stations, but if you want flexibility and choice in the future, you need to insist on DICOM General Purpose Worklist  If not there yet (insist on a firm, dated commitment, with guaranteed interconnection)

References

 DICOM Standard Home Page  http://www.dclunie.com/dicom-status/status.html

 DICOM Newsgroup  news:comp.protocols.dicom

 My E-mail (Dave Harvey)  mailto:[email protected]