Centera and Medical Imaging

I've spent some time this year writing about how digital archiving is a perfect match for EMC Centera. Digitized records, photos, videos, and audio tracks from the JFK Library represent fixed content, and Centera is optimized for the storage of fixed content. It's also scalable enough to store the number of objects being generated at the library.

Centera's compliance and tamper-proof authentication capabilities are also being deployed in the US Court System.  I've written a post about King County District Court in Seattle that provides more detail.

Another match made in heaven when it comes to Centera is medical imaging.  I mentioned in a post earlier this year that the country of Finland has purchased Centera as the centerpiece of a deep repository for safely keeping the medical records of all of its citizens.

When an entire nation chooses to store all of its medical records on Centera, it is safe to say that the product has arrived as a technology of choice for hospitals and medical applications.  In fact, no less than 1,700 healthcare organizations are currently using Centera. And that number is growing.

Here's why.

PACS

Picture Archiving and Communication System (PACS) software generates medical images from procedures such as ultrasounds, medical resonance imaging (MRI) and mammograms.  These images are large, and depending on the size and population served by the medical facility, storage capacity for these images can grow on the order of 1-2 terabytes per month.  Trying to manage a tape-based solution for that amount of data becomes more difficult from a system management perspective, and more slow from a performance perspective. The storage and retrieval of medical images are better served by a disk-based technology.

But not just any disk-based technology.  Medical images stored on Centera reap the additional benefits of content addressing.  Content addresses assist not only in the retrieval of medical images but they also contain timestamped hash values that assist in verifying that the image is the original. 

Ease of Management for Medical IT Staff

Hospital IT staff are attracted to Centera's ease-of-management characteristics. What are these characteristics?  There are several:

• Location independence.  Centera is addressed as a TCP/IP network port. There are no disk groups to provision, no file systems to create, and no database tables to form. Medical images are sent to a network port and a content address is returned.
• No server software.  Application servers connected to Centera do not need special device drivers or connectivity patches. The applications running on these servers have pre-integrated with Centera and communicate over standard TCP/IP networks.
• Configuration-free capacity upgrade. At a growth rate of 1-2 TB per month, capacity upgrades are inevitable.  With Centera, disks are added on the fly with zero need for manual configuration to recognize the new disks. Again, there are no disks to group, LUNs to build, or file systems to configure.
• Technology refresh. As new releases of Centera provide faster and/or larger hardware capabilities, new nodes can be placed side by side with the legacy Centera, and object-based "image migration" can occur. Both systems can stay up and running during this process, and validation of image existence can occur when the refresh is complete.
• No need to perform backups.  Not only is the Centera self-healing in the face of failures, but hospitals usually replicate their Centera configuration(see DR discussion below).

When you describe Centera's self-management value to an IT specialist at a hospital, they get it. Immediately.

Disaster Recovery

Is there any more important set of data than the medical records of an individual?  The protection of these records from disaster and system failures are of the utmost importance to the medical community. Centera supports system-to-system replication of these medical images.  What's more, every application that integrates with the Centera system receives built-in support for automatic failover to a secondary Centera. When an application fetches a medical image from a primary Centera (via the use of a content address), any failure to retrieve that image will automatically result in the retrieval of that image from the secondary Centera (using the identical content address).

There are no special management commands or scripts that must be run against the secondary Centera that "promote" it to be a primary store.  This also eases the administrative burden of managing a replication topology.

Retention

The laws for retention of medical records vary from country to country, but it is not uncommon for a country to mandate that medical images are kept forever. This fact steers customers towards Centera for two reasons:

1. Centera's implementation of retention is unique in the industry. When the PACS application stores an image it specifies the appropriate retention period (e.g. forever). This retention value contributes to the content address (the hash value); there is no way to tamper with it. Attempts to delete the content will result in failure. The Centera is "locked down", i.e. there is no way for an administrator to "log in" and "change permissions" on a directory or file, or anything of that nature.
2. If documents are being retained forever, then inevitably someone is going to ask for a medical image that was stored 5-6 years ago.  Image retrieval must complete on the order of seconds (i.e. tape cartridge retrieval is not an option). Centera's retrieval time satisfies the hospital requirement; any image can be returned in a deterministic amount of time, regardless of the age of the image. This is especially important for images retrieved when a patient is on the verge of a surgical procedure.

Now You Know Why

To satisfy all of the requirements listed above would be burdensome for any non-Centera system.

Hospitals are NOT going to buy a system that is immature and/or unreliable. Centera is neither. Check out this press release from 2004. Fraser Health is still using their Centera and is currently up to 240TB capacity!

Fraser Health is one of the hospitals complying with an "infinite retention" mandate from their government (Canada).

I hope to provide more information about Centera in the medical community in future posts.

Steve