Radiology departments in the U.K. National Health Service (NHS) became completely filmless in 1997. When we analyze the process of moving from films to filmless, we realize the key role played by the global, open interoperability standard: DICOM.
The DICOM standard allows the following:
- Any vendor's machine/scanner to produce images in the open DICOM standard format, i.e., the x-ray department and modalities act like DICOM image sources
- Images produced from any vendor's machine can be indexed to a standards-based directory, ensuring consistency of metadata, i.e., DICOM directory
- Images produced from any vendor's machine can be archived to a standard-based DICOM archive
- A standards-based DICOM directory could be queried by any vendor's open standards based DICOM viewer
Dr. Neelam Dugar is a consultant radiologist at Doncaster Royal Infirmary, U.K., and former chair of the Royal College of Radiologists' Imaging Informatics Group.Many vendors have created a combination of a DICOM standards-based entity, i.e., PACS, which is a combination of three components: DICOM directory, DICOM image archive, and DICOM image viewer.
The U.K. government has pledged to make NHS paperless by 2020. Studying the situation more closely, the principles behind paperless and filmless are very similar. We need to look at open standard formats, open standard metadata indexing, open standards-based archiving, and open standards-based viewer.
Vendor-neutral archive companies are actually forging ahead with a vision of a paperless NHS. The interoperability open standard they have chosen is XDS (cross enterprise document sharing).
The NHS uses paper in many forms, including the following:
- Correspondence (unstructured narrative-based data): clinic letters, discharge summaries, operation notes, histopathology reports, radiology reports, etc.
- Images: cardiology images, ophthalmology images, etc.
- Graphs: audiograms, ECGs, etc.
- Structured coded data: lab results, etc.
Hence, the interoperability standard chosen needs to support multiple formats, including DICOM (for images), PDF (for unstructured documents), clinical document architecture (CDA) (for structured documents with coded content), etc. The indexing must be fairly generic and simple to support multiple specialties and data types. Viewing of the documents and images in the archive must be available to any vendor's viewer, using open standards for display.
Why have VNA companies chosen XDS as their interoperability standard of choice? There are three essential reasons:
- XDS repository supports archiving of multiple formats: PDF for unstructured narrative data, CDA for structured data content or combination of structured and unstructured data content, DICOM manifest (allowing images to reside in a local DICOM archive), JPEG, etc.
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XDS registry has some very simple, minimal, but clinically relevant metadata requirements:
- Patient-related metadata: ID, name, date of birth, sex, address
- Author-related metadata: name, job title, specialty, institution, legal authenicator
- Document-related coded metadata: document class, document type, healthcare facility type code, practice setting code, event code (document related keywords), document creation time, reference ID (to link docs), title of document (if more sophisticated coded data is required within certain documents, XDS standard supports CDA documents, which can contain more coded content along with narrative content for different document types)
- XDS consumer (XDS viewer): any vendor's viewer/display can display the metadata and documents stored within the XDS registry and repository, using standard transactions.
With an XDS registry and repository, VNA vendors have positioned themselves very well to support NHS hospitals to move forward in support of the 2020 paperless agenda. They are offering a combination of XDS registry for indexing documents and images as well as XDS repository, i.e., a standards-based but multiformat archive. However, they have left the image and document display to be the remit of any suppliers, including PACS vendors. This allows for the registry and archive to be interrogated by any vendor's XDS viewer.
However, the key challenge remains in incorporating clinical, paper-based documents, graphs, etc., into the VNA, and wrapping documents with XDS metadata. The metadata wrapping needs to be done without generating inefficiencies in the clinical workflow.
As many of us have seen, the film-to-filmless transition did take time. We have seen scanners that were unable to output in DICOM in the early days, and we also know workflow change is always challenging. VNA vendors collaborating and adopting the standards-based approach can learn lessons from what made PACS such a global success. They can help us move from paper to paperless within healthcare organizations.
Dr. Neelam Dugar is consultant radiologist at Doncaster Royal Infirmary, U.K., and former chair of the Royal College of Radiologists' Imaging Informatics Group.
The comments and observations expressed herein do not necessarily reflect the opinions of AuntMinnieEurope.com, nor should they be construed as an endorsement or admonishment of any particular vendor, analyst, industry consultant, or consulting group.
