Transcript A Working Group of Our Own (DICOM WG-26)

A Working Group of Our Own
(DICOM WG-26)
Bruce Beckwith, MD
Department of Pathology
Beth Israel Deaconess Medical Center
Harvard Medical School
Boston, Massachusetts
Current State
Future State
Outline
DICOM overview
DICOM pathology support
Use in Pathology
Issues to address
DICOM
Digital Imaging and Communications in Medicine
Initially drafted as jointly sponsored effort of the
American College of Radiology and the National
Electrical Manufacturers Association (ACR-NEMA),
which became the DICOM committee in 1998
Ver. 1 released 1985
– Physical 50 pin hardware abstraction layer standard
– Never implemented
Ver. 2 released 1988
– Initial interest from radiological manufacturing community only
DICOM V3.0 released 1992
Visible light supplement 1999 (endoscopy/microscopy)
DICOM Governance
Voluntary standards group
Housed at NEMA in Virginia
Currently 26 working groups
Participants
– Industry
– Professional and trade groups
– Standards developing bodies and government
agencies
– Anyone who has a material interest
Pathology in DICOM
Visible Light working group was initial
home
Created Supp. 15
Minimal pathology activity since then
Dec 2005, created a new group for
Pathology (WG-26)
Working Group 26
Open to all interested parties
3-4 meetings per year
70+ subscribers to the mailing list
35+ organizations
9 countries
Working with IHE (Japan and France) and
HL7 Pathology groups
DICOM Supplement 15
Support for
–
–
–
–
–
–
–
gross images
microscopic images
accession numbers
case history
SNOMEDTM nomenclature and others
some imaging system specifications
compatible with all DICOM database systems
How DICOM is Used
To communicate between image sources
(radiographic instruments) and PACS
To communicate between PACS and display
workstations
To communicate between RIS and PACS
To communicate between image sources and
enterprise image archive
Image Exchange
DICOM standard is for communication
related to digital images
Uses externally defined file formats to
encode the image data
Includes metadata with the image data
Uses an object oriented data model
16-part standard document
– http://medical.nema.org/dicom/2006/
Service Class Wrapper
Typical VL Message Components
Header Constructs
•Patient demographics
•Study capture parameters
•Equipment parameters
•Pixel/voxel dimensions
•Diagnostic data
Image Data
•Primary image plane data
•Overlay data
•Arbitrary waveform data
•ROI data
•Diagnostic ROI-localized modifier data
•Access/authentication/watermark data
Optional Components
Structured Reporting Data
•Self-referential XML schemata
•Clinical Data
•Specimen Data
•Tissue Array Data
•Research Access data
•Clinical Trial Data
•Chain of custody data
•………………….
•Ancillary Schemata/DTD definitions
•Ancillary XML
Picture Archiving &
Communication Systems
Store images acquired by multiple
instruments
Serves images to various workstations
Uses DICOM for messaging
Typically only utilized for radiology images
May have workflow limitations
Enterprise Image Archive
Centralized storage for medical images
Share across many departments
Not limited to radiology or even DICOM
Not tightly coupled to any workflow
Can be write once – read many (no
deletion)
Imaging Comparison
Radiology
–
–
–
–
–
–
–
–
digital acquisition
automatic image capture
clinician interpretable
many patient requests
large storage needs
digital images save money
large budgets
strong standards for
storage and transfer
Pathology
– analog primary data
– manual image capture
– hard to interpret for nonpathologists
– few patient requests
– extreme storage needs
– digital imaging costs more
– modest budgets
– limited pathology specific
standards
Current State in Pathology
Many PACS vendors are compliant with Visible
Light images for pathology, endoscopy, etc.
Growing number of imaging products targeted at
pathology are DICOM compliant
Anatomic pathology laboratory information
systems offer limited image management
Veteran’s Administration:
Pathology imaging vendors must be DICOM compliant and
store images in VISTA PACS
Small, but growing adoption of DICOM
Barriers to Adoption of
Current Products
Turf
– PACS systems have traditionally been the domain of Radiology
– Movement toward storing all medical images in a central location
with a single viewing mechanism still in infancy
Workflow
– May need to manually annotate files with image description,
accession number, etc.
– If sending to PACS, need to order study first
Cost
– Image acquisition and annotation takes time – no extra
reimbursement currently
– Slide scanners and storage are costly
Path PACS
Humin Tec (Korea)
–
–
–
–
PACS system for pathology departments
21 installations, all in Korea
Communicates with standard radiology PACS
Also offers station for specimen photography
Apollo Telemedicine (USA)
– PACS system allows acquisition and storage of
images
– Installed at Milwaukee Veterans Administration
Hospitals
– Images can be stored in VISTA imaging system
Academic Center Efforts
Univ. of Pittsburgh
– AP LIS is image aware
– Gross specimen photos and single field microscopic
images saved
– Transmitted to Enterprise Image Archive
– Clinicians can see only selected images on
completed cases
– Main clinician interest is specimen photos
– Main pathologist use is conferences
Issues to Address
Technical
– Need for additional data elements (block, slide, slide status,
more detailed imaging system description, etc.)
– Support for whole-slide microscopic images
DICOM is limited to 64k x 64k pixel images currently
– Support for multi-resolution (pyramidal) formats
– Support for navigating and selecting a region of interest from
within entire slide image
– Support for multispectral and hyperspectral modality images
Non-technical
– Suggested workflow and use examples (IHE)
– Support for DICOM from LIS vendors
Resources
DICOM web site:
medical.nema.org
RSNA DICOM Intro
www.rsna.org/Technology/DICOM/intro/index.cfm
Medical Imaging FAQ:
www.dclunie.com/medical-image-faq/html