High seas and sandstorms test equipment durability

Radiology has formed part of the military's medical arsenal for more than 100 years. Reports from the Boer War of 1899 to 1902, for example, describe both sides using crude x-ray units to find bullets lodged in injured soldiers.

The sophisticated medical imaging equipment armies today take into combat ranges from lightweight handheld ultrasound machines to whole-body CT scanners. War puts the theoretical advantages of high-tech radiological solutions to the test.

The hospital ship USNS Comfort was fitted out with a state-of-the-art angiography suite before heading to the Middle East earlier this year. The vessel provided medical services to U.S. and U.K. troops and Iraqi prisoners and civilians during the U.S. war against Iraq and its unsettled aftermath. A new telemedicine system installed in the 1000-bed floating trauma center further enhanced the ship's existing digital imaging capabilities.

All x-ray imaging on the Comfort is performed using computed radiography, following a systematic series of equipment upgrades and installation of PACS. Film processing had previously proved to be a problem, according to Capt. Jeffrey Georgia, an interventional radiologist on the Comfort. When the ship experienced high seas or weight transfer caused it to list beyond a certain point, chemicals from the wet processor would spill onto the floor and melt the tiles. Switching to CR solved this difficulty.

But the mobility of radiology equipment can still cause problems not generally experienced on dry land. The control panel for the Comfort's new digital subtraction angiography unit, for example, is on wheels. While this is an advantage in most hospital interventional suites, moderately heavy seas can make the control panel move on its own. Georgia fixes the wheels with wedges to prevent the unit from trundling around the room while he carries out procedures.

"We're pretty much used to the motion of the ship," he said. "It's incredible watching the vascular surgeons doing a bypass graft on a gunshot wound. You see everyone swaying back and forth as the ship rocks."

Replacement of low-grade angiographic capabilities with a high-tech digital system has worked well, Georgia said. Power fluctuations hampered work with the unit at first, but the ship's engineers quickly solved this problem. Medics had a limited time to familiarize themselves with the new equipment and faced life-or-death situations shortly after arriving in the war zone. In one case, the radiology team performed a successful pelvic embolization on a critically injured patient who was bleeding profusely and too ill to undergo surgery.

"Taking a machine from acceptance testing two days before the ship sailed to doing one of the most complicated trauma cases there is was quite a steep learning curve," Georgia said. "We were fortunate that it worked out well."

Radiologists on board the Comfort were also able to test the ship's new telemedicine system. Faced with particularly difficult head trauma cases, they exchanged images and advice with a neuroradiology specialist back in Bethesda, MD, via a secure satellite link. This teleradiology consultation allowed them to double-check their preliminary diagnoses. Field hospitals used conventional x-ray imaging, so some patients flown to the ship brought hard-copy films with them, Georgia said.

Military radiology teams on the ground in Iraq had their own challenges. Staff based in desert field hospitals faced a daily battle with sand, according to Surg. Cdr. Peter Buxton, a senior radiologist with the U.K. armed forces and head of telemedicine for the Defence Medical Services.

"When there is a severe dust storm, you cannot see across the width of the tent. And, yes, I do mean the tent - outside it was worse," Buxton said. "All pieces of equipment had dust sheets over them, and the floor was swept out several times a day. X-ray cassettes were also cleaned more often than normal."

Air-conditioning shielded the tented hospital from desert temperatures that soared during the day and plummeted at night. This ensured that the temperature of developing chemicals could be controlled, he said. Electricity cut out periodically, however, often without warning.

Buxton cited three main criteria for imaging equipment used in war: reliability, robustness, and versatility. Ultrasound is especially helpful in diagnosing a wide variety of combatant injuries and illnesses, 90% of which can be classified as disease nonbattle injury. Diagnosis of appendicitis may not sound as critical as dealing with bombs and bullets, but it is still important to keep fighting troops healthy, he said.

While field hospitals were equipped with plain-film x-ray and fluoroscopy equipment, patients requiring CT could be evacuated by helicopter to a nearby hospital ship. CT can play an important role in assessing body and head trauma due to conflict or other causes, Buxton said. The U.K.'s RFA Argus and the Comfort both ran CT examinations throughout the war on Iraq, although neither ship offered multidetector imaging.

The aging CT scanner on board the Comfort was used fairly heavily during the four-week attack and stood up far better than expected, Georgia said. Radiology staff sometimes had to consider whether the scanner was going to overheat during busy periods, and the estimated duration of a scan, as well as urgency of the injury, dictated patient order. Some exams performed routinely on CT in modern trauma centers, such as pulmonary embolism evaluation, were simply not possible.

"It's the sort of CT scanner that would be found in a small community hospital in the U.S. It's not very fast and doesn't have all the bells and whistles that most trauma centers have now," Georgia said.

He is looking forward to seeing multidetector CT on the Comfort next time the ship sets sail from Baltimore. Funding has just been approved for a scanner upgrade. Georgia is pressing for a replacement that meets the requirements of any modern trauma center, and that includes CT fluoroscopy for real-time drain placement. Installation of speech recognition software, or at least recruitment of a dedicated transcriptionist, would also save considerable time, he said. The ship's radiology team performed over 2000 exams in the first five weeks after weighing anchor in the Middle East, generating over 8000 images. They then hand-typed each report themselves.

Having a PACS, on the other hand, has speeded up delivery of medical care considerably. Monitors are available throughout the 12-storey ship, enabling clinicians to preview images while radiologists are still completing their diagnostic reports. An enormous amount of work went into making the complex computer network function efficiently and ensuring that the right images appeared in the correct place whenever demanded, Georgia said.

"All the clinicians knew was that they would order a cross-table, lateral cervical spine x-ray, and, two minutes later, they would be looking at it right there on the screen in the casualty receiving area," he said. "We were complimented by a number of people on that, which made us feel that we were doing our job."