Amid worries over high medical radiation exposure, vendors are looking to software and gadgets that help keep images sharp, and patients and radiologists safe. Nowhere was this more in evidence than at last week's annual meeting of the Radiological Society of North America in Chicago, where companies touted advances slashing radiation dosage by 50 to 80 percent for some CT and X-ray procedures.

"What the vendors are moving toward are technologies with...[software] reconstructions," Dominic Smith, vice president of global marketing for CT and nuclear medicine at Philips Healthcare, told DOTmed News at the show.

Philips' entry in the field is iDose, technology Philips expects to ship with its flagship CT solution Brilliance CT by the second half of next year. "It's a reconstruction technique to reduce the dose by 80 percent, particularly in the body, where you have a lot of high organ dose," Smith explained.

Smith said with iDose, a procedure that would typically deliver 6 to 8 millisieverts of radiation now only gives 0.9 mSv.

Another program, called Step and Shoot Complete, expands Philips' Step and Shoot Cardiac, their version of the CT technique first introduced at RSNA 2006.

"In things like Step and Shoot Complete, using our technology reduces the dose but maintains or improves image quality," said Smith.

The new technology allows reduced-dose imaging of the chest, thorax and lung using the step and shoot method, and can be applied to anyone whose torso is 19.7 inches (50 centimeters) or bigger.

But iDose and Step and Shoot weren't Philips' only entries in the low-dose stakes. Many Philips employees roaming their sprawling booth in the North Hall sported lapel-pin-like badges that turned out to be another dose-conscious item: DoseAware. These badges monitor radiation exposure in real-time and project the results onto a screen. Philips says DoseAware is primarily meant for radiologists, nurses and radiologic techs performing interventional procedures to know exactly how much radiation they're getting as they move around the room, thereby allowing them to limit their exposure. Philips hopes DoseAware will prove a useful complement to the radiation-monitoring badges rads routinely wear, but which only give monthly, not real-time, totals.

Putting it in Context

"X-rays penetrate almost anything but all cause harm to human tissue," said Donald Barry, Ph.D., X-ray product manager of ContextVision, which is in the business of making dose-reduction technology. "The higher the dose, the more harm to human tissue."

ContextVision, a 26-year-old company headquartered in Linkoping, Sweden, hopes to limit that harm with its latest image enhancement products.

ContextVision's applications are unbranded and sold directly to OEMs, so they have a policy of not revealing who packages them with their equipment. "We're 'Intel inside,'" said Barry. But ContextVision does claim to now work with about 40 equipment makers.

They call the proprietary algorithm their product depends on GOP, a set of adaptive filters that remove noise and format the image in the way the OEM wants. "It's a way of looking at contextual structures," explained Barry, and ContextVision claims it mimics the way humans pull visual information from their environment. In the latest version, captured images are compared against around 95 data libraries to help reconstruct a low-dose image so that it's diagnostically equal to a normal-dose image.

Barry said their technology draws on advances made in graphics processing units partly spurred by, of all things, the video game industry. "We're riding the GPU power curve and cost curve," he said.

At this year's RSNA, their big debut was the GOPView XR-2 Plus for digital X-ray machines. Barry said while they don't have clinical results in yet, he expects the dose reduction to come in at the 40 to 50 percent range.

But ContextVision was able to share results from some pre-clinical tests. On Friday, researchers presented data from a trial using their image-enhancement filter on angiographies performed on pigs. ContextVision claimed that the filtered low-radiation dose angiograms had comparable quality to normal-dose images, while cutting radiation dosage during interventions by half.

Latest iterations

One of the biggest low-dose trends at the show was "iterative reconstruction," offered by both Siemens and GE.

IR is a set of nearly noise-impervious algorithms that helps computers reconstruct 2-D or 3-D images. Historically, their use in med tech has been low, because of their slow speed. But Siemens and GE seem to have overcome any earlier limitations.

IRIS, Iterative Reconstruction in Image Space, Siemens' version, achieves a claimed dose savings of up to 60 percent. GE's ASIR, Adaptive Statistical Iterative Reconstruction, packaged with their LightSpeed VCT XTe and their Discovery CT750 HD, gives a claimed dose reduction of 40-50 percent.

But IR isn't all these two companies had to offer. GE says their SnapShot pulse technology can help cut cardiac CT doses up to 83 percent. And Siemens says advances in scanning speed for its SOMATOM Definition Flash Dual Source CT scanner mean it can do a complete scan of the chest in 0.6 seconds.

Faster scans mean lower doses. "Siemens Definition Flash gives low-dose development, especially in ER pediatrics and sub-mSv cardiac scans, 0.85 mSv in comparison to the average of 5 to 12 mSv," Andre Hartung, a Siemens spokesman, told DOTmed News.

No matter how these products turn out, the low-radiation trend looks to be robust. "Where CT is going is [toward] routine, high image quality, low dose," said Philips' Smith. "So you have the high image quality, but you're not going to pay the price of [higher] dose."