Image recovery is a necessity for any PACS system to protect against image loss. Unfortunately, when Vendor Neutral Archive (VNA) providers do not offer the necessary archival layers for protection, images are put at significant risk. Lost and destroyed images may go undetected until clinicians attempt to read those images when needed to support patient treatment, putting care teams and the patient in harm’s way when images are needed most.
Providers of VNA technologies have suggested that VNA is a solution to image availability, and that the system guards against image loss. Commentary from leading analysts including Gartner has increased awareness of VNA as a means to share DICOM images from one brand of PACS system to another. However, many administrators remain unaware that VNA technologies used on their own are insufficient for ensuring image availability. In fact, all images which are held in unprotected VNA repositories remain at risk of loss.
Though the definition of VNA technology would suggest it provides image protection and availability, standard VNA approaches are focused only on DICOM and lack essential capabilities. Critical gaps in standard VNA approaches include lack of file-level protection, abstraction, and storage-level handling. Without these capabilities, images stored in VNA repositories remain at risk of loss from disk failures, silent data corruption, and erroneous file deletes. These risks occur frequently, yet are often overlooked in hospital environments.
Understanding the different layers of archiving
It may seem counterintuitive to state that a VNA does not equal image availability. After all, isn’t the market definition of a VNA all about image archival? Unfortunately, this definition of VNA ignores important requirements needed to provide complete image availability. To begin, it is necessary to establish how the definition of VNA is incomplete by first looking at the word “archive.” Not surprisingly, this word has different meanings to different people. When you examine the different contexts, you realize that there are different levels of archiving and that they all build upon one another.
The diagram above depicts these different layers and how they work together. The physical storage layer includes the physical devices that are used to store, or archive, data. The abstraction layer defines how the data is written such that it can be written across many different storage devices and is often accessed through an API. The file layer views data as being stored in files and provides archive methods that deal with files of any type, containing many different types of data. The file layer knows about these files but is unaware of the contents of them. The content layer often stores its data as files but is aware of the content within the files such as the DICOM header information in a DICOM image.
Understanding these different layers, what they provide to archival and how they build upon one another is the key to understanding what is missing in the market definition of VNA and why VNA does not equal image availability.
Time for a new approach
IT professionals, including PACS administrators and others responsible for ensuring image availability, often use archive technologies as a stop-gap method for preserving images in case of failure. In this scenario, archive is used as a type of backup. These archives are most commonly either dumped to removable media, such as CDROM or held on spinning disk. Both methods can fail, threatening image availability. Furthermore, archive technologies are not designed to enable rapid, efficient recovery of protected images.
Put simply, healthcare IT professionals need to realize that this approach to VNA is incomplete if it does not include capabilities for data protection which ensure image availability. Using a VNA technology on its own to create an image archive does not safeguard those images from loss, and experts agree that the traditional definition of VNA is not appropriate in today’s hospital environments.
Joe Marion, principal of Healthcare Integration Strategies, LLC, notes that patient wellbeing is put at risk if image protection is not ensured.
“Many administrators remain unaware that a standard VNA is insufficient for ensuring image availability as DICOM-level archive technologies are not designed to preserve multiple file copies, on multiple types of storage, with embedded signature validation. As a result, patient care is put at risk by these organizations because their images are not adequately protected,” said Marion. “What is needed to ensure image availability is an approach to VNA that is based upon a solid foundation of data protection. Healthcare organizations should familiarize themselves with the risks that exist and how to overcome the problem by taking an approach to VNA which is built on a solid data management foundation.”
Building a complete definition of VNA
It’s worth noting that vendors that provide solutions to healthcare IT are often different from vendors supporting healthcare clinical users. Part of the reason that most approaches to VNA are incomplete is because vendors focused exclusively on clinical users have capability sets built exclusively at the content layer. The reverse is also true: IT products for data management that are used by healthcare IT are often not defined with healthcare in mind and, as a result, ignore the needs of clinical users. Healthcare IT must support clinical users and their workflows, and they need products that help them support both groups.
Therefore, a complete definition of VNA must include support for all content types at the content layer and all of the layers of archival. This approach allows all content within the healthcare environment to be managed by content archival. An approach which is limited to DICOM only means that managing other types of data will be overly complex, costly and unsustainable for healthcare organizations in the longer term. File archival functionality provides a powerful method to protect unstructured data stored in files, and protect those files from loss. A VNA that is built upon a strong foundation of file archival is secured against image loss or corruption.
The premise of this article is that a VNA as most commonly defined in the market today does not equal image availability. This is true because most vendors offering VNA capabilities are limited to the content layer and do not include a solid foundation for data protection. A solid foundation for data protection requires support for multiple layers of archival. In most healthcare organizations, therefore, DICOM images and other critical healthcare data remain vulnerable to loss and corruption even when residing in VNA repositories.
What’s required is an approach to VNA which bridges the gap between the DICOM content layer and the lower three layers of archival. A sufficient VNA approach must be aware of clinical modalities and requirements while also maintaining storage-agnostic flexibility with policy-based archival to ensure cost-effective use of tiered storage systems. Only this unique combination will close the divide between what clinicians want and what IT needs in order to provide a sufficient approach to VNA which protects against image corruption and data loss.
Jim Beagle is president and CEO of BridgeHead Software. He brings a proven track record of delivering business growth, with more than 25 years’ experience in director-level positions across technology, distribution and consulting. Recently, Jim was EVP of worldwide sales and services at CarbonFlow Corporation. Prior to that, he was CEO of Extraprise International, divisional VP of Object Design, European director of UIS (one of the companies that formed Sprint) and held sales/marketing roles at ICL (now Fujitsu).