WG 13 (Visible Light) – "Full-slide Microscopy Images”
Secretariat
European Society of Cardiology
Secretary
Pr. Dr. Med. Rudieger Simon
Co-Chairman
Emmanuel Cordonnier ETIAM (interim)
emmanuel.cordonnier@etiam.com
Co-Chairman
Juergen Thiem, SONY (interim)
juergen.thiem@eu.sony.com
Date of Last Update:
Work item editor:
March 17, 2004
Bruce Beckwith (CAP)
bbeckwit@bidmc.harvard.edu
Scope:

To extend the DICOM standard beyond the currently available Visible Light images, to include fullslide digital microscope images, which are now available from a variety of pathology imaging vendors
and which will likely come into clinical use in the next few years.
Roadmap:
 Identify vendors and users who are interesting in participating in this process
 Inventory the current methods in use for compressing/storing and transferring full-slide images
 Inventory the current methods for navigating and viewing selected portions of a large image
 Determine what changes should be made to the Visible Light IOD(s) to accommodate full-slide images,
if changes are necessary
 Determine the optimal methods for storing, selecting and retrieving portions of these images and
potentially define-new/modify Service Class
Short Term Goals:



To modify the Visible Light IOD to include information related to full-slide digital microscopy images
To address whether any changes in transfer syntax for this IOD would be needed.
To address methods for seleting and retrieving a particular area of interest from a very large image
object (perhaps using the Web access to DICOM persistent objects methodology).
Current Status:
 WG13 has been working on supplements related to MPEG video since September 2002. Balloting on
two proposals has recently concluded.
 A number of pathology imaging vendors and potential users have been contacted and have expressed
interest in participating in the process including Apollo Telemedicine, Aurora Interactive Microscopy,
Aperio Technologies, Interscope Technologies, Trestle Corporation, the Armed Forces Institute of
Pathology and the College of American Pathologists, Association for Pathology Informatics.
Future Work Items:
Risks:

Come too late and too many proprietary systems are in use. This would be particularly unfortunate if
healthcare institutions end up having separate storage, retrieval and viewing systems for different types
of digital images related to the same patient.
Challenges and Opportunities:


Several pathology vendors (Apollo Telemedicine, M-Scope and Olympus) are currently offering
systems that can create and view DICOM compatible microscopic images. These systems are primarily
generating small “field of view” or “region of interest” images. Other vendors are considering adding
support for DICOM images, partially in response to their clients being interested in creating DICOM
compatible image archives.
There are several manufacturers (such as Aperio Technologies, Interscope Technologies and Bacchus)
which are currently offering medical microscopy systems capable of capturing an image of an entire
microscopic slide. These files are extremely large (4 to 40 Gigabytes currently and potentially much
larger) and are being compressed, stored and viewed using a variety of proprietary methods. There is


no standard for creating and storing or transferring these objects currently. Since the use of these
systems is increasing and they are felt to be likely to become widely adopted in the future, the time is
correct for engaging the vendors and users to ensure that this form of imaging is supported in DICOM,
providing more impetus for pathology vendors and users to embrace DICOM.
While current visible light IOD’s are capable of encoding a very large image, there are practical issues
surrounding methods for storing, navigating and selecting areas of interest. Using current compression
techniques, these images are at least 2-4 Gigabytes in size. While it is possible to transfer the entire
image (say to store in an archive or PACS system), it will be necessary to have a way to navigate a low
power (magnification) overview of the slide image which is small enough in size to be readily
transmitted between the PACS/storage location and the viewer without undue delays. It may be
necessary to store multiple different magnification versions of a slide image as well, and store a "tiled"
series of Slide Coordinates Microscopic VL images. Once a region of interest is identified, then it will
be necessary to retrieve a small portion of the overall image at full resolution. Subsequent navigation of
the image may require retrieving additional adjacent portions of the slide image. Even if current IOD’s
are adequate for encoding these large images, we will need to add data fields indicating what type of
image (full slide at full resolution, full slide low power overview, region of interest) as well as some
sort of information regarding where in the entire image a smaller image is located. Retrieval of a region
of interest may be challenging as well since the storage system will need to extract a small portion of
the total image to send back. If the low power overview image(s) are stored as separate files, then we
will need to define how to relate them to the full resolution image.
If no extension of the present standard is required, at least "education" shall be made of users and
vendors, thanks to a "white paper".
Relationships to other Standards:

Web Access to DICOM Persistent Objects