CT vendors renew emphasis on safety and speed

March 8, 2008 CT vendors renew emphasis on safety and speed John Bonner -------------------------------------------------------------------------------- Safety first is the watchword for developers and users of CT technology. While imaging power and range of clinical applications continue to expand, so too does the ingenuity applied by vendors in finding new methods to reduce patient radiation exposure.Most research into cutting the radiation dose for each scanning procedure has focused on enhancements to the imaging hardware. Considerable effort has gone into improving the design of the x-ray tube and improving the speed and efficiency of data capture.But a Swedish company appearing for the first time in the ECR exhibition hall has devised a different approach to minimizing patient risk. SharpView, established in May 2007 as a spinoff from the Linköping-based digital imaging company ContextVision, has developed software technology that allows radiologists to set a lower x-ray dose while preserving image quality.With conventional CT, low dose normally results in poor images, but SharpView has created an adaptive nonlinear filter based on mathematical algorithms that detect and eliminate noise during processing. The inspiration for these ideas came from studies on human vision, according to CEO Magnus Aurell."The biological eye is superior to any computerized solution in its reception and understanding of images. Visual information is registered in the human brain in a continuous cycle, with a variety of dedicated cells identifying, defining, and classifying image structures. The methodology within SharpView CT evolved from computer simulations produced in this research. Since its development and refinement, the technology has been utilized and integrated into a wide range of medical equipment," he said.In tests using the technology, radiologists have been able to cut the dose used in head examinations by about 30% and in chest imaging by up to 70%, Aurell said. For high-risk abdominal scans, the dose reduction achieved is between 40% and 50%.The image processing software is integrated within the hospital's existing CT image flow and is DICOM-compatible. It can be used with all types of CT scanners and can be tailored to fit the hospital's preferences for handling its imaging data.Meanwhile, the global giants of the CT industry have also been busy opening up new approaches to the safety issue. Toshiba Medical Systems is demonstrating the Aquilion ONE dynamic volume CT scanner, which enables physicians to scan an entire organ — heart, brain, or liver — in a single rotation lasting 0.35 seconds. The company expects the product to be particularly useful as a diagnostic aid in cardiology investigations, because the entire heart can be captured in a single heartbeat. By cutting radiation exposure, it opens up the possibility of new applications for CT in areas such as pediatrics.Aquilion ONE offers 16 cm of anatomical coverage using 320 detector elements at 0.5 mm each. This gives it the ability to carry out a complete examination in a single scan and eliminates the need to reconstruct data from several points in time, thereby increasing diagnostic confidence. By allowing both a comprehensive scan and functional imaging, the technology should limit the need for duplicate tests, reducing both risks to the patient and costs to the hospital, according to the vendor.Siemens Medical Solutions has addressed the need to improve efficiency by introducing Somatom Definition AS, an adaptive system that provides different functions depending on the patient's situation and offers new applications for CT. The product's adaptive 4D spiral facility enables the clinician to carry out functional imaging (or perfusion images of blood flow over time) specific to the particular organ being imaged. In the case of stroke, for example, physicians can use perfusion imaging not only for a small part of the brain but the whole organ.The equipment also benefits from the company's adaptive dose shield technology. This addresses concerns that as detector size and slice counts grow, the problem of unnecessary radiation before and after the scan becomes more acute. This is particularly so in facilities where older gantry designs have been updated with newer detector designs to save costs. The Siemens technology blocks unnecessary exposure to radiation before and after the spiral scan, ensuring that any dose received is clinically relevant.Improvements to gantry design are a significant feature of the latest product in Philips Medical Systems' range of CT devices. The Brilliance iCT is a 256-slice scanner that allows the capture of highly detailed 3D images of the entire heart within the duration of two beats. The gantry rotates four times a second or 22% faster than most current systems. In trials, it has been shown to reduce a patient's radiation dose by up to 80%, bringing direct benefits to both doctors and patients, according to the company. "The new Brilliance iCT scanner was specifically designed to make the job of clinicians easier and improve the experience of the patient," said Philips CEO Steve Rusckowski. "Our innovations demonstrate Philips' commitment to enable healthcare providers to devote attention to their patients, not just the technology."

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