Big news today as DICOM supplement 145 has been approved, support for whole-slide microscopic images. This means the [very] large images used in digital pathology can now be stored in a DICOM-compatible fashion, and promises future interchange between digital pathology systems and tools and other systems such as PACS systems used for Radiology and other medical imaging modalities.
The key approach in storing the [very] large multi-resolution multi-planar whole-slide images (illustrated at right, top) was to map subregions from each layer into a DICOM series (illustrated at right, bottom). This approach required relatively minor conceptual changes in the DICOM standard and will make implementation by vendors with existing DICOM-compatible products easier, helping to foster adoption of the standard.
Creation of this supplement by NEMA Working Group 26 was a cross-vendor effort including digital pathology companies like Aperio, medical imaging companies, and support from the College of American Pathologists. The completed supplement may be downloaded from the NEMA website.
This addition to the DICOM standard complements a previous effort by Working Group 26 which resulted in supplement 122, a specimen model for Pathology. Together the supplement include:
- One major new DICOM Information Object Definition (Whole Slide Imaging) with new concepts to manage the huge WSI data set
- A major revision of a DICOM Information Entity (Specimen) with a rigorous information model
- 56 new data elements added to the DICOM Standard in 14 new or revised modules
- 7 new or revised DICOM structured data templates and 18 new defined value sets
- 80 new coded terminology concepts added to SNOMED, and 36 added to DICOM
- 40 pages of explanatory information about pathology workflow and imaging
With this approval, it is natural to ask, "what will change?" The immediate effect will be a clear signal that digital pathology vendors are committed to interoperability and open standards, which will help foster adoption of the technology. Further out, digital pathology companies and other medical imaging vendors such as those who make PACS systems will enhance their products to support the new standard, enabling interoperability between systems for digital pathology images.
We at Aperio have been involved in Working Group 26 since the beginning of these efforts and enthusiastically support creation of standards for interoperability, as part of our "open systems" approach. This is a big step and we thank everyone involved who helped make it happen. We would especially like to recognize Dr. Bruce Beckwith, chairman of working group, and the College of American Pathologists whose vision supports these efforts.