A reader of the story about the hospital SmartCard project asked me if the card could store an MRI. The short answer is no, not today, but in the long term, yes for sure. The most important short-term role for the smartcard is authentication. The best example to explain that is Clear. The Clear smartcard contains a digital representation of each iris, all ten finger prints, and your photograph. When you present your Clear smartcard at the airport, there is no doubt that you are who you say you are. You then "fly through airport security" to your destination. Imagine the same at the hospital — no more clipboards and filling out information they already have. It seems like a dream today but in the not too distant future we will be able to "fly" through the healthcare process, experience personalized medicine, and feel like the providers are giving us concierge treatment.
Back to the MRI question, where are the MRI’s — and CAT scans, X-Rays, and mammogram’s — stored? They used to be on film and the patient would carry them around from specialist to specialist and the hospital would keep football field size storage rooms loaded with them. Progressive hospitals today use a PACS (Picture Archiving and Communication System). The performance and reliability of PACS are critical to a hospital’s ability to provide patient care. The PACSs have gotten better and better but physicians are continuously raising the bar. Understandably, CIO’s and CFO’s are concerned about the fast growth of storage needed as the imaging technology supports higher resolutions, more images per study, and escalating federal and state government storage requirements. Physicians want online access 24×7 from the office, hospital or their home to not only the MRI you had today but the one you had a year ago and maybe ten years ago. Hospitals have tried to cope with the increased demand by offering online storage for very current images and "nearline" storage for those that have been archived. Nearline often means that the image is stored on tape and can be brought online if a special request is made. Increasingly physicians and patients do not feel there is anything "special" about it — they expect all data to be online all the time just like Amazon. The online retailer has every order they have ever received since the company started in 1995 online and available 24×7. Easy for them some might say. An order for a book is trivial compared to a digital MRI image.
How big is a digital MRI image? A recent cervical spine MRI contained 160 images and was approximately 60 megabytes in size. About the same as 200 iPhone pictures or 20 iTunes songs. Let’s suppose a community hospital has 25,000 patient visits per year and that on average a patient has two image studies performed. That would be 50,000 times 60 megabytes which equals 3 terabytes. Now let’s consider what size storage is available and how much it costs.
In the mid 1970’s an IBM "disk pack" for a mainframe computer had a capacity of 200 megabytes — about three MRI’s. The entire storage system could contain eight "drives" for a total of 1.6 gigabytes. It seemed like a lot at the time. The cost of the disk drive that the disk pack fit on was nearly $200,000. During the last thirty years the cost has continuously plummeted while the capacity has skyrocketed. The Apple Time Capsule has a capacity of one terabyte and costs $499. IBM has a new storage system that offers up to 1,176 terabytes in a single system. Soon we will be talking about petabytes (1,000 terabytes) and then exabytes, zettabytes, and yottabytes. When I had written a story about yottabytes back in 2005 a reader said the term should be "alottabytes". A yottabyte is 1,000,000,000,000,000,000,000,000 bytes.
The bottom line is that there will be plenty of storage to put all our images online. The key challenge is the management of the data — keeping it secure, backed up, resilient to disaster, and easy to access and manipulate. Many providers will decide to put all the data in the "cloud" and let someone else manage it. Amazon’s Simple Storage Service (S3) is the tip of the iceberg. They charge $0.15 per gigabyte per month of storage used. IBM offers a wide range of storage services and also partners with many healthcare information technology companies.
The normal reaction would be that having all the images online is too expensive. I think many of us will instead think of it like electricity. Healthcare providers use a lot of electricity and some are beginning to cogenerate their own to save money. One thing they don’t do however is consider having some of their electricity "offline" or "nearline". It is online 24×7. That is the way we will soon think of medical images.

• Yottabytes story from 2005
• Other patrickWeb stories about healthcare