Meet the Challenge of Image Storage Demands

Over the past two decades, improving technology has vastly changed digital image storage. In most cases, higher quality images are taking up less space. But, that’s not true for radiology.

As image quality advances, the amount of storage space required balloons. The size and number of images needed for quality patient care is quickly outstripping storage capacity. Chances are, you’re either already grappling with how to upgrade your storage or you will be soon.

“Beginning with PACS through to digital tomosynthesis, we’re continuing to see an increased size of exams,” says James Whitfill, MD, chief medical officer for Arizona’s clinical integrated care network, Innovative Care Partners. “It can stress your network and your current storage capabilities.”

The question is, how do you find an option that meets your current and future image storage needs for an acceptable price tag?

The Image Size Problem

More detailed images improve diagnostic capabilities, but they also put greater strain on the IT department. And, the stress is two-fold, says Todd Thomas, chief information officer with Austin Radiological Association (ARA).

First, your IT department is responsible for migrating all your data. As your storage needs expand, they must determine how to move it to a new platform. The more data you have, the longer the process.

“If you have multi-terabytes or petabytes of data, the fear is by the time you’re done migrating to a new platform-and it can take months-it will be time to migrate to yet another vendor who can better accommodate your needs,” he says.

Second, latency-how quickly you retrieve images from storage-is a frequent problem. Larger image sizes tax your digital bandwidth, making it more difficult to both transfer images into storage and pull them back. For many providers, he says, image-access wait times over three seconds are unacceptable.

Finding the Right Solution - One Group’s Experience

According to Thomas, ARA faced this conundrum in 2014 when its clustered storage solution couldn’t handle the increased size need caused by a switch from 2D to 3D mammography. At first, the group purchased 55 terabytes (TB) of storage, but it quickly filled up. Eventually, ARA bought 174TB of space, adding 304 gigabytes (GB) monthly. Repeated purchases were neither time- nor cost-effective, he says.

Cloud storage was the answer. With it, ARA could immediately purchase additional storage space at a reasonable price point, and the organization met its providers’ latency requirement of three-second maximum wait times. Not only did ARA expand bandwidth from 100 megabytes to 500 megabytes, but it also pre-planned to limit wait times.

“We use DICOM routers to pre-fetch cases that the physicians need to see in the middle of the night and push them to their work stations,” Thomas says. “They’re ready and waiting when they arrive in the morning.”

Selecting The Right System

There’s no universal cookie-cutter storage solution, Thomas says. But, there are several things you should consider to pick the right system. Engage your stakeholders in discussions to ensure you’re selecting a product that works best for everyone. You’re more likely to get their buy-in if they’re included, says Whitfill, who is also the Society of Imaging Informatics in Medicine president-elect.

• Latency: Ask your end-users to identify the maximum latency they can tolerate.
• Risk: Dissect their acceptance of risk. Are your colleagues comfortable having only one back-up copy if part of the storage system fails, or do they want a second? If your vendor no longer supports your equipment, are they comfortable with third-party maintenance contracts that extend on-premise storage life but also introduce future software update costs? Are they even comfortable putting sensitive health data into cloud storage?
• Know your modality mix: The types of imaging you produce determines your storage needs, Whitfill says. Breast and cross-sectional imaging, such as multi-slice CT, produce large amounts of data, requiring more storage capacity.
• Retention requirements: Know how much data your colleagues want to keep. If your sub-specialty requires you keep large amounts, select a solution with enough storage capacity that grow with you.
• Assess your growth: Figure out how much storage space you’re currently using and estimate how it might expand within five years. Take into consideration modality upgrades or moves toward enterprise imaging, Whitfill says. Including other image-producing specialties, such as diagnostic pathology, greatly augments your storage needs.
• Identify your system management: If you’re a larger group, you might have an IT department on-site fully versed in managing your storage solution. However, if you’re a small group, Whitfill adds, make sure you have an outside vendor in place who can trouble-shoot problems.

Storage Options

After you’ve assessed your needs, you can select the storage products best suited for your group. Mix-and-match more than one system to best protect your data, Whitfill says.

In addition to the cloud, most practices choose from three storage capabilities.

• Hard disks: These are the bread-and-butter of the storage business. This on-premise option works well for most providers and is, typically, an economical solution.
• Flash or solid-state storage: Similar to RAM in a computer, this storage option is much faster than hard disks, but it’s also much more expensive. It’s most frequently used to handle heavy data needs associated with enterprise imaging systems.
• Magnetic tape: Tape storage is slow and inexpensive. If you’re comfortable with slow retrieval times, tape is a good option for maintaining a third back-up data copy.

Side-Stepping Storage Failures

There are a few things you can do to avoid a breakdown in your image storage system, Whitfill says. These strategies can likely stop problems before they arise or fix them quickly if they hit.

• Test your system: Whitfill recommends you aggressively test your main and back-up storage systems to ensure they’re actually working as expected. Check to make sure your second or third copies of images are saved properly and can be easily retrieved.
• Monitor frequently: Don’t assume everything is running smoothly. Have your IT department or storage vendor schedule periodic assessments to pinpoint problems in infancy. The sooner you identify problems, the easier the fix. Also, decide who tackles repairs so nothing is forgotten.
• Watch capacity: Periodically check to see how full your storage is so you can upgrade before you run out of space.
• Choose familiar technology: Select an image storage solution that’s familiar to your local IT group. You may select a technology only your storage vendor can manage, but you limit yourself to having only one maintenance option.

“Adopt a technology that can be supported by your PACS, your storage vendor, and your local IT team,” Whitfill says. “If they have the same visibility and capability to support and manage it, the extra set of eyes is critical to ensuring you have redundancies in place to keep your image storage up and running.”

Most importantly, Whitfill says, concentrate on purchasing the storage amount you’ll need to meet your requirements for a few years. Don’t over-buy-you’ll waste money.

“If you think you’ll need 10TB over three years, don’t buy 100TB today. The price of storage is falling so quickly,” he says. “It will probably be 50 percent to 70 percent cheaper when you actually need to buy more space.”