If your enterprise is similar to most current hospital health information technology (HIT) architecture, you have clinical/data silos everywhere. This is nothing to be ashamed of; you are normal. But in the coming age of healthcare delivery, silos must be replaced with interoperability. One key to interoperability will be an integrated medical image archive. While most consider image archiving as specific to cardiology or radiology, the fact is you have imaging elsewhere in your enterprise whether you know it or not. Determining the best archive solution is dependent on the size and scope of your imaging needs across the enterprise.
Most likely, your institution has heard of, and may even be in the process of, procuring a vendor neutral archive (VNA). The VNA market is in the emerging stages of combining a multitude of technologies into a single unified platform. This platform typically consists of a hierarchical storage manager, intelligent archive feed by HL7 interfaces, health information exchange (HIE) integration engine with XDS-i conversion, DICOM archive, non-DICOM storage archive, DICOM normalization tools often seen in the picture archiving and communications system (PACS) neutral archive market and an encompassing univiewer that can display all stored data types.
With so many features and variations, it is hard not to simply run out and procure the nearest vendor. Beware, this is akin to running to the car dealer without any plan or requirements other than, “I need a car for the next 10 years.” Your best strategy is to understand and calculate your enterprise needs now and your vision for the future prior to choosing a VNA vendor.
There are three types of VNA products now available in the archive market: Full VNA, hybrid VNA and PACS neutral archive (PNA). A fourth category might include the vendors touting their PACS solution as a VNA. As a result, confusion is rampant in the community, since the definition of a VNA depends on which vendor you speak with. Vendor selection in this market will have a significant impact on the clinical and technical functionality of your archive. Thus, you must first understand what defines the three categories of VNA.
Full VNA
A full VNA is not only an all-in-one solution, but also offers the ability to fully utilize non-DICOM objects without manipulation or intervention. A full VNA provides an embedded and supported universal viewer that is capable of displaying DICOM and non-DICOM objects within a single application without wrapping or encapsulating the object simply to archive the object and make it useful with current technology.
Full VNAs typically offer the following abilities:
• WebServices for header/database index publication
• Certified hardware virtualization
• Hardware-agnostic implementation option
• ILM (image lifecycle management)
• Routing/prefetch rules
• Data normalization tools
• Native DICOM and non-DICOM object archival in native format
• Single patient record across all disciplines
• Single integration point for image enablement for all archiving clinical systems
• Unified fully integrated image viewer for DICOM and non-DICOM objects
• Ability to utilize best-of-breed DICOM viewers from a third party
PACS and cardiovascular information systems (CVIS) are by default architected to archive image data in perpetuity. With many facilities reaching 50+TB, the data center has become a graveyard of images that haven’t been accessed in years.
A full VNA will provide you with a one-stop shop for all archiving needs and dissemination of all image data to electronic medical record (EMR) and health information exchange (HIE) exchanges by default. They will provide viewer support or access to the data if a third-party viewer is warranted by your analysis. A full VNA will archive all data types.
Hybrid VNA
A hybrid VNA offers the basic core infrastructure of a full VNA but often does not include a univiewer by default that ties the entire package together. These abilities typically include:
• Web services for header/database index publication
• Certified hardware virtualization
• Hardware-agnostic implementation option
• ILM (image lifecycle management)
• Routing/prefetch rules
• Data normalization tools
• Native DICOM and non-DICOM object archival in native format
• Single patient record across all disciplines
• Ability to utilize best-of-breed DICOM viewers from a third party
A hybrid VNA is lacking in a unified viewer. It allows you, the customer, to choose best-of-breed when selecting a viewer for your enterprise. It provides the viewer a direct access link (DAL) to the object storage location.
Hybrids are capable of storing non-DICOM objects, but typically by default do not provide an ability to utilize the non-DICOM object unless the chosen third-party viewer is capable of displaying that file type. Consider this a finger-pointing session between the clinical application system and the third-party unified viewer. The VNA vendor will simply provide storage and access to the object.
PACS Neutral Archive (PNA)
PNAs are simply third-party DICOM archives that are typically rebranded by existing storage vendors with an inbound interface to keep the records in sync with the enterprise. They offer the ability to store and archive images from multiple DICOM systems, but usually lack the ability to store non-DICOM data without wrapping or encapsulation. They often also usually lack image lifecycle management (ILM) and Web services to publish the data to an HIE. There are many vendors in this space touting VNA.
It is important to understand that many archiving systems use proprietary objects or TIFF formats for image and data storage. This category of VNA vendors recommends these objects be wrapped or encapsulated in a DICOM wrapper. This renders the object unusable by the clinical archiving system. It solves the ability to disseminate the object, but destroys the ability for the archiving system to utilize it, because it lacks the ability to retrieve that object once stored.
Define Your Need
Evaluating your enterprise needs is a difficult and sometimes overwhelming endeavor, especially when you venture into the non-DICOM world. For radiology and cardiology, DICOM is a format we are all very familiar with. However, DICOM is not typically the standard outside of these two imaging service lines.
Non-DICOM will bring with it very interesting integration storage methods and different retention and compression rules not typical in the PACS environment. It is wise to bring in an expert who has the ability to look at your enterprise with new eyes and your strategic roadmap, while providing you with a list of requirements your organization needs for a unified storage platform. Once you have your requirements, you will know what type of VNA to entertain.
The VNA analysis will uncover what future system dataflow and workflow would look like for all clinical imaging departments. Wrapping or encapsulation might make sense, but if that data is irretrievable by the clinical archiving system, it disrupts the clinical workflow. Other questions to consider include:
• How does your enterprise plan to integrate into an HIE or unify all imaging to enable a comprehensive patient record for your EMR?
• Do you plan to build an EMR API integration for each clinical system with a unique viewer?
• Do you plan to utilize your PACS and force radiology workflow onto the enterprise?
• Does your enterprise need the capability to intelligently utilize storage while having all image data adhere to your disaster recovery plan?
Most facilities plan carefully for a PACS installation, then allow IT to decide on an archive strategy. A VNA impacts clinical workflow, and the clinical side of the house must validate dataflow and workflow of the system-of-choice.
A VNA will and can touch every clinical imaging system and acquisition device in your enterprise. The planning for a VNA must be comprehensive, and you’d better get it right. Your VNA will likely be around longer than any other clinical archiving system you currently have today.
Jonathan Shoemaker is a frequent speaker and writer on healthcare technology topics and VNA. He is a senior consultant at Ascendian Healthcare Consulting.
April 22, 2024 
