By Dan Hosseinzadeh
Co-Chair, DICOM Working Group for Pathology (WG-26)
DICOM WG-26 continued to push the boundaries of interoperability at DICOM Digital Pathology Connectathons throughout 2019. Similar to 2018’s successful Connectathons, these events showcased the use of the DICOM Standard to achieve interoperability of Whole Slide Imaging between different vendor’s equipment and software. Learn more about DICOM for Digital Pathology Interoperability.
In 2019 WG-26 organized two Connectathon events at the following conferences:
European Congress of Digital Pathology (ECDP) 2019, Warwick, UK; and
Pathology Visions (PV) 2019, Orlando, US
Pathology Visions 2019
With 11 vendors participating at PV’19, this was the largest Connectathon event to date. In attendance included 6 scanners, 3 archive/PACS, and 4 viewer vendors.
Participating vendors continue to test and improve their DICOM digital pathology capabilities at each event. Here are the results from 2019:
Scanners: All 6 vendors created images that could be displayed by viewers, however only 3 created images that met Connectathon requirements.
PACS/Archives: All 3 vendors were able to accept images and provided conformant methods to retrieving images.
Viewers: All 4 viewers were were able to retrieve images from multiple scanner through all the archives.
Through the 2019 Connectathons, WG-26 has identified two key issues with the DICOM standard:
Z-Stack: There was confusion with images having Z-stack information. Vendors inserted layers in different (but valid) ways, however this led to confusion among some of the viewers. Possible solutions include developing a guideline for vendors and/or extending draft Application Profile for WSI, which is being developed by WG-26. The profile describes some specific usage scenarios, such as pyramid structures, and how they should be handled by vendors to enable streamlined viewing and processing of images.
Colour Management: Colour management was not always implemented. Some ICC profiles were too large and, as a result were slow to retrieve using a normal metadata retrieval request. A correction proposal may be required to address retrieval of ICC profiles more efficiently (i.e. separately).
2020 Road Map
With the success of prior Connectathons, DICOM will be hosting two more events in 2020 in Europe and North America:
European Congress of Digital Pathology in Porto, Portugal (May 2020); and
Pathology Visions in Orlando, US (October 2020)
Future events will focus on increasing vendor participation and expanding the scope of demonstrations. Standard development will be required to broaden the scope of the demonstrations. These developments include standards for exchanging metadata, improved support for image analysis, as well as practical clinical workflows for primary sign-out and artificial intelligence (AI).
WG-26 is currently working with IHE PaLM to complete a draft standard for metadata data exchange between acquisition modalities (i.e. scanners) and laboratory information systems (LIS), known as Image Acquisition Profile (IAP). We hope that his work will be completed in 2019 so that it can be integrated into the 2020 Connectathons, allowing more participation and engagement from LIS vendors.
Development of IAP also enables WG-26 to transition the organization and management of the Connectathons to an IHE Connectathon framework for future events. IHE’s framework goes beyond a demonstration of interoperability by providing a quantitative and objective framework for evaluating conformance of participating vendors against standards for interoperability.
Lastly, WG-26 is currently working on reviewing the capabilities of DICOM’s annotation model for pathology. We’ve started by documenting the perceived limitations in DICOM for different use cases (e.g. WSI image analysis). Once all members have provided input, the group will address the limitations of DICOM and started developing correction proposals and/or propose extension of DICOM for the unique requirements of pathology. We hope to incorporate some of these developments and more examples of image analysis in the Connectathons in 2020.