By William Matthews

Last spring, frequent mortar attacks on Baghdad's Green Zone repeatedly sent doctors and technicians scrambling for cover, slowing the installation of digital pathology equipment at the Army's 86th Combat Support Hospital.

The equipment permits doctors there to send scanned images of tissue instantly to Washington for analysis by the U.S. military's best pathologists.

"You get a diagnosis within hours rather than days," said Paul Stone, a spokesman for the Armed Forces Institute of Pathology.

Bringing digital pathology to Baghdad is part of an ongoing program of upgrades to the U.S. military's telemedicine capabilities. "We're trying to provide better consultation services to all of the major military hospitals," he said.

Using advanced digital scanners, computer networks and sophisticated software - some created for U.S. spy agencies - it is possible to make high-quality, high-resolution images of tissue samples and send them anywhere in the world for analysis.

"This is game-changing technology," said Dr. Bart Harmon, chief medical officer at Harris Healthcare Solutions.

A major player in military and commercial information technology, Harris is among a number of companies hoping computers and software will soon replace the glass slides and microscopes that pathologists have relied on for more than a century.

With new digital technology, "you can pan across, zoom in, zoom out - you get instant magnification," Harmon said. "It's just as good as looking through a microscope."

But he added that the real payoff comes from new capabilities that surpass what a microscope can do.

Software developed by Harris allows multiple pathologists to study the same tissue sample at the same time - even if they are continents apart. Each pathologist sees the same slide on his or her computer screen. When one pathologist magnifies a portion of it, the others will see the same magnification.

And if one pathologist draws a circle around an area of particular interest, the others will see the circle in real time.

Notes and other annotations can be attached to the slide and shared instantly by all of the viewers.

"What you see on the remote end is identical to what you see as the primary pathologist," Harmon said.

Instant second opinions
The technology promises to transform pathology. "If I'm a pathologist and my job involves driving to a remote hospital two hours away and back, digital pathology means I can stay in my office," said Dirk Soenksen, chief executive officer of Aperio Technologies. "And if I want to share a slide with someone to get a second opinion, it can be done very quickly."

A digital image can be transferred instantly via the Internet, meaning that second opinions are just seconds away.

Digital technology also means expertise becomes available wherever in the world it's needed, Harmon said.

That's especially important to his former employer, the U.S. military. Before accepting his current position at Harris in January, Harmon was chief medical information officer and director of information management at the Military Health System.

The Army has many small hospitals that have a single general pathologist on staff, Harmon said. Digital tools give that doctor the ability to consult with the military's most experienced and specialized pathologists no matter where they are or when they're needed.

The pathologist "could connect to someone at Walter Reed or the Armed Forces Institute of Pathology or the Navy in San Diego and get a consultation without having to ship them the slides," he said.

For a doctor in the middle of surgery, "if a tumor turns out not to be so ordinary, you might be able to get a consultation on the fly and change the patient's treatment versus having to close the patient up and ship the slide or even ship the patient" to a specialist, Harmon said. "It brings expertise into the hospital."

And diagnosis is faster for patients. "It's a quality-of-life thing," he said. "You don't have to wait for a week or over a weekend. You will know in a few hours."

"In military circles, you have experts in Landstuhl, [Germany]; Walter Reed; on the West Coast; and in Hawaii," Harmon said. Digital pathology means "you have consultants available 24 hours a day. That's a tremendous benefit."

Digital pathology transformed
Until recently, the digital pathology business was the province of about a dozen small technology companies. "Digital pathology did not exist four years ago," Soenksen said. "Our company defined it and created the market."

Figuring out how to produce a digital image of a microscope slide was a formidable problem, he said. Because images of a very high resolution are essential for examining tissue samples in detail, scanned pathology slides become gigantic digital files.

"In 1999, it took eight hours" to create a single digital image, he said. "We developed scanning technology that can do it in a couple of minutes."

Transmitting and viewing such large files also posed challenges. Bandwidth limitations and inadequate computer processing power caused large files to download in fits and starts and then stall while being viewed.

Aperio's technology compresses files to eliminate those problems, Soenksen said. For example, it compresses a 5G file into a couple hundred megabytes for transmission, then decompresses the file when it reaches the recipient.

Aperio also provides predictive software that anticipates what the pathologist will want to see next and preloads those portions of the slide, Soenksen said. Thus, if the pathologist is moving to the right on the slide, the software will preload the next section of the slide to the right and store it in the computer's cache, ready for instant use, he said.

Harris uses a different approach, but officials won't reveal much about how the technology works. Harris spokesman Sleighton Meyer said the procedure involves "post-processing of the gigabyte images after they are digitized."

"The technique provides file-access times that are independent of file size," he said. "Thus, files can be kilobytes, megabytes, gigabytes or terabytes in size, and yet the file-access time is the same."

The technology impressed Dr. Jeff Shogan, a cancer specialist at the University of Pittsburgh Medical Center.

The Harris technology's "ability to move large files and allow you to go from low to high magnification is extraordinary," he said. "You have the sense you are doing it in real time."

Shogan is chairman of the board at Cancer Treatment Services International, which announced it will use Harris' imaging technology in radiation oncology.

Impact on small practices
Although digital tools promise to transform pathology in the United States, they're likely to have their biggest impact in developing countries, Shogan said.

The technology will give countries with few pathologists access to hundreds or thousands worldwide, he said.

In the United States, digital pathology could lead to the eventual disappearance of small pathology practices and departments at many hospitals, Shogan said. Instead, services are likely to be contracted out to larger operations populated by specialists and sub-specialists.

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