PACS is the global leader in the world of health informatics. Underpinning the success of PACS is the global open and vendor-neutral standard of DICOM. PACS has been the most universally successful clinical IT system, and radiology has been the speciality that has led the world in the adoption of DICOM and PACS.
The current PACS contracts are coming to an end in the U.K., and hospitals are reviewing the successes and failures of PACS. This analysis is relevant for other Europeans too.
Dr. Neelam Dugar is a consultant radiologist at Doncaster Royal Infirmary, U.K., and chair of the Royal College of Radiologists' Imaging Informatics Group.The following are some of the deficiencies in PACS, for which enterprise vendor-neutral archiving (VNA) holds promise in the future:
Medical images outside radiology: PACS works well in radiology, but there are other departments producing images (ophthalmology, medical photography, endoscopy, etc.) that still are in data silos. Enterprise VNA will store DICOM images from multiple specialities.
Document handling: PACS and DICOM work well for images, but documents are not handled well. This even applies to radiology documents -- radiology reports and radiology requests. Although these are linked documents to the radiology images, DICOM has not been successfully adopted by nonimage vendors like radiology information systems (RIS), electronic health records (EHR), etc., which create and display these documents.
Messaging standards of HL7 v2 are inadequate for document display. HL7-clinical document architecture (CDA) is the emerging universally accepted medical document standard. With the move by HL7 to become an open standard with no licensing fee, we are likely to see a global surge toward its adoption of CDA. At the most basic level, a CDA can be simply a pdf document encapsulated with xml metadata. Unlike PACS, an enterprise VNA is capable of storing documents as HL7 CDA.
Multispeciality indexing and metadata: A PACS and DICOM directory is sufficient for indexing radiology metadata. However, the metadata stored by DICOM is insufficient for multidepartment images and documents. This is where cross-enterprise document sharing (XDS) (from integrating the healthcare enterprise, IHE) emerges as a superior indexing methodology for an enterprise wide multispeciality image and document indexing. An enterprise VNA indexes to an XDS Registry.
From radiology to EHR view: Whilst PACS has been limited to images and radiology, enterprise VNA will provide an integrated view of images and documents generated in multiple departmental electronic systems. Data in VNA can be accessed and viewed by any XDS consumer compliant system from any vendor (standards-based clinical portal).
Sharing of documents: The DICOM standard works well for sharing of images with other organizations, but it has had limited value in ability to link and share documents like radiology reports and requests. The emerging IHE standard of XDR-I allows for documents and images to be linked and shared with other organizations. Enterprise VNA due to adoption of XDS for indexing can easily adopt XDR-I.
Data ownership and end of migration: Despite DICOM being a vendor neutral standard, migration of data from PACS has been difficult. With a migration engine included, enterprise VNA holds promise for easier migration of data at the end of contract. An IHE profile/standard for migration for DICOM images, HL7 CDA documents, and XDS registry metadata indexing would help to standardize the migration process.
Life cycle management: Enterprises struggle with the process setting up an effective electronic data deletion process, as currently enterprise data is held in multiple systems. Enterprise VNA holds promise of centralizing the life cycle management of electronic medical images and documents.
Access control via active directory: Whilst enterprise VNA brings about the benefits of bringing together images and documents from multiple sources, thus effectively creating an integrated electronic health record, there is also a need to be able to restrict access to certain "documents/images class/types," including XDS metadata terms, to certain staff groups. Active directory-based access control to documents held in enterprise VNA is essential.
Audit trails: By including the audit trail and node authentication profile of IHE within the enterprise VNA, there would be centralized recording of audit trails, rather than audit trails being recorded and stored in multiple systems.
Following the success of PACS, enterprise VNA holds a lot of promise for the health informatics community. However, like PACS, the real test will lie in the ability to adopt vendor-neutral standards like XDS/XDS-I for indexing and HL7 CDA as the document standard. Intelligent customers will be looking at true and proven vendor neutrality by monitoring companies' performances at IHE connectathons. For that purpose, go to connectathon-results.ihe-europe.net.
Dr. Neelam Dugar is consultant radiologist at Doncaster Royal Infirmary, U.K., and 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.
