June 2011

Information Not-So-Super Highway
By Timothy W. Boden
Radiology Today
Vol. 12 No. 6 P. 10

What do you do when the information superhighway is more like a dirt road? Imaging Associates of North Mississippi Magnolia found a way to get maximum use from less-than-maximum bandwidth.

Five years ago, IT Director Cavett Otis ran into a serious data bottleneck while setting up connectivity between his Tupelo, Miss.-based practice, Imaging Associates of North Mississippi Magnolia, and the Tippah County Hospital in Ripley, Miss. Despite Ripley being the county seat, this tiny town of about 5,500 offered little in the way of data connectivity.

Imaging Associates is a full-service radiology practice offering a full menu of imaging services to area physicians, including six hospitals in northeastern Mississippi and southcentral Tennessee, according to founder and managing partner C. Michael Currie, MD. Its six physicians employ another 12 contracted doctors to provide “everything from plain films and mammography to PET scans and MRIs of the brain, abdomen, and spine. We do ultrasound, CT scans, CT angiography, and cardiac evaluation as well. There really isn’t anything we don’t do—although we don’t do very many interventional vascular procedures,” says Currie.

Imaging Associates faced a challenge common among imaging organizations: It served a broad geographic area that lacked the latest broadband infrastructure. Otis and Imaging Associates knew from prior experience that T-1 connections likely wouldn’t deliver enough improvement to justify each line’s $1,500 monthly cost. The practice was disappointed with T-1’s performance at its Tupelo office, even after tripling the number of T-1 lines to six.

“You’d think going from 3 MB to 9 MB would make a dramatic improvement,” says Otis, “but we never saw the big gains we’d hoped for.” The local cable company also proved inadequate for transmitting images, leaving 1.5-MB asynchronous DSL as the only remaining option.

Clearly, Imaging Associates needed a way to optimize its wide area network (WAN) connectivity. While considering options offered by dominant player Cisco as well as “a couple smaller companies,” Otis met the local sales representative for Boulder, Colo.’s Circadence Corporation, a company specializing in IT system performance improvement.
“We met in an unusual way,” says Otis. “The Circadence rep happens to play tennis with my wife.”

When DSL Is Top of the Line
Otis found it hard to believe Circadence’s claims for dramatically improving data transmission speeds for a fraction of the cost associated with competing systems. But Circadence offered a 60-day free trial during which Imaging Associates could evaluate system performance firsthand. Imaging Associates agreed, and Circadence installed its MVO appliances at each end of the connection in less than one day. The company’s technicians configured the software and brought the system online.

Otis describes seeing immediate, “jaw-dropping” speed increases: CR images previously requiring from 11/2 to 21/2 minutes now came across from Ripley to Tupelo in 25 to 30 seconds using the same 1.5-MB asynchronous DSL connection.

The current method for transmitting data, transmission control protocol (TCP), has been around for a long time—from the days when data files tended to be small and “flat,” explains Circadence Chief Technology Officer Robert J. Shaughnessy. Since then, data files—especially graphic image files—have grown to previously unimagined size. While the IT industry has pushed hardware and cabling speeds to achieve greater bandwidth, available service varies considerably across the United States. In rural Mississippi, some areas have only recently acquired cable and asynchronous DSL data services. The cable company can provide multiple T-1 lines but at a high cost to the subscriber. Technologies like optical carrier, capable of delivering hundreds of megabits per second, are a ways off.

Large files and burgeoning network traffic suppress data speeds to an intolerable crawl across such networks, so the industry has devised several workarounds collectively referred to as “WAN optimization.” Depending on a user’s specific needs, WAN optimization approaches use techniques such as data compression and data caching. Other more complex methods attempt to address data duplication and error correction.

Many typical approaches to WAN optimization are not only complicated for the end user but also expensive to deploy. Equally important, standard data compression for images tends to degrade quality. Compression’s data loss and corruption leave images unreliable for medical purposes so WAN optimization that relies on file compression must use a “lossless” protocol.

 “Not only must medical images arrive exactly as transmitted, but the process must be very secure,” says Shaughnessy. Compliance with HIPAA standards adds additional complexity to the solution.

In bringing its WAN optimization products to the medical market, Circadence capitalized on its extensive experience in providing optimization to the U.S. Department of Defense in situations requiring data accuracy and critical security across a spectrum of connection types and platforms.

Efficient Packets
Its MVO product line uses a combination of software and hardware to achieve results like those reported by Imaging Associates personnel. “TCP communications breaks a large image file into small pieces, packs the pieces into data ‘packets,’ and transmits them to the receiver,” explains Shaughnessy. “The receiving end takes those pieces and reassembles the image for viewing on the display. Along the way, the sender and receiver also communicate to check for errors and to retransmit lost information packets.”

The old TCP method, while very reliable, isn’t very efficient. “During the transfer process, many sent packets are sent without being filled to capacity. Our algorithm repackages the data so that every packet is full,” Shaughnessy says. That translates into fewer packets required per image.

Compare the process with a railroad: Two trains travel the same distance at the same speed carrying exactly the same freight. One train pulls 100 boxcars with contents varying from 5% to 60% of capacity, including several empty cars. Let’s say the train overall is loaded to only 25% of its true capacity. The second train, pulling cars packed to 100% capacity, will obviously need only 25 boxcars. Its entire load will arrive sooner and will require far less track space. That means more room on the track for better-packed trains.

After processing by the Circadence MVO system, tightly packed data files—without compression or caching—are shorter and can require less time to transmit. The data use available bandwidth more efficiently, so you get faster results without actually accelerating the connection speed—and that saves money.

Otis says the costs associated with the installation hardly compared with the T-1 solution. The purchase price for the Circadence host unit in Tupelo was less than one month’s subscription for T-1 at both ends. The remote unit at Ripley cost little more than one half of that. In other words, a one-time investment totaling less than two months of T-1 service yielded far more dramatic transmission time reductions.

The only additional expenses came in the form of annual technical support, the costs of which run about 8% of the original purchase price—a few hundred dollars per year. Otis reports that Imaging Associates has placed only a few support calls over the years to get help resolving minor problems such as an altered IP address at a client site.

Cost-Effective Performance
“Circadence’s cost-to-performance ratio is really very good,” Currie says. “It’s really inexpensive, especially when you consider the transmission time improvement and its ease of use for the physicians.” It has made a difference in the doctors’ productivity because they spend much less time waiting for an exam to download to a workstation.

Optimizing data transfer not only helps keep the physicians moving but also allows them to move around. The low cost justified Imaging Associates’ installation of Circadence at all its service points, making specialists immediately accessible from wherever they happen to be working.

“As a neuroradiologist at this location, I can quickly receive an image series from any of our locations, take a look, and give them a pretty good idea of what’s going on right then and there,” Currie says, adding that faster response, better service, and improved communication with providers in the network translates to better patient care because specialist expertise is more easily available.

Physicians’ efficiency improves not only because they can spend more time reading and less time downloading but also because they can distribute work more easily. If one location finds itself deluged with a high volume one day, it can enlist the help of doctors working at a less busy facility by quickly transmitting some images off site for reading and interpretation.

The Circadence MVO system’s flexibility allowed Imaging Associates to add another dimension to its physician efficiency. It installed the MVO system on Web servers at both its main Tupelo office and at the 164-bed Magnolia Regional Health Center approximately 60 miles away in Corinth, Miss. That gave physicians secure, high-speed access to image files on either server at any time using their MVO-equipped laptops and home computers with Web access. Otis said the Circadence appliances are completely transparent to other users but provide performance jumps for Imaging Associates’ providers.

WAN-optimized connectivity has allowed Imaging Associates to offer services to remote locations where it wouldn’t make sense to assign a radiologist. The same medical staff can serve more patients scattered across thousands of square miles. Even as it seeks to add another facility to its client network, the practice feels less pressure to recruit additional doctors.

The technology works well for Imaging Associates. With a reasonably low-cost investment, the practice has realized performance gains in all its installations across a variety of platforms. The Circadence solution has provided dramatic improvements on everything from T-1 lines and Web servers to asynchronous DSL and cable modems as well as remote PCs and laptops.

“It’s not often that physicians are even aware of the technology behind their IT needs,” Otis says, “but at Imaging Associates, all the member physicians recognize our performance gains and refer to Circadence by name. I think that says a lot.”

— Timothy W. Boden is a freelance writer and healthcare consultant based in Starkville, Miss.


What Is WAN Optimization?
Transmission control protocol’s (TCP) reliability has kept it active for almost 40 years, but today’s huge and ever-growing data demands prove taxing to the point of network congestion and frustratingly slow connectivity. The IT industry has addressed the problem with different solutions through the years. Major approaches include the following:

Data compression: Compression programs reduce actual file size. Image files are generally reduced with “lossy” compression techniques that actually remove information not generally noticed by the human eye. “Lossless” compression is possible but tends to be slow, and it can’t shrink file sizes as much.

Wide area file services: This relies on file-server consolidation across the wide area network (WAN), moving commonly used files from remote servers to the data center for more efficient access.

Data caching: Caching creates easily accessible copies of data objects that are likely to be accessed by users in the future. Based on usage, the software predicts and adjusts what objects will likely require future access.

Protocol optimization: Optimizing programs modify TCP behavior and “pack the data pipe” with information. Networks with large bandwidth-delay product (large fat networks) often benefit the most from this approach.

WAN optimization takes many forms, but all approaches seek to move more information over the network in less time. Until we have a new file transfer protocol, TCP will continue to challenge IT specialists to invent new and better ways to improve efficiency.