Health Imaging & IT - January 2008 - (Page 16)

A Look Inside Next-Generation Multidetector CT The Dose Question Radiation dose is in the international spotlight, especially after the recent New England Journal of Medicine article that showed CT scans could be responsible for as much as 2 percent of all cancers in the United States in the next 20 to 30 years due the radiation exposure. The importance is compounded by the great increase in CT scans, with study authors David Brenner, PhD, DSc, and Eric J. Hall, DPhil, DSc, of Columbia University estimating “that more than 62 million CT scans are currently obtained each year in the United States, as compared with about 3 million in 1980.” Thus, hospitals and imaging centers are attempting to devise strategies to minimize radiation dose to patients while maximizing imaging benefits. Vendors are on the same path—with all four multidetector CT vendors projecting dose reductions to patients in the range of 80 percent with their next-generation systems compared with currentgeneration scanners. Here’s how the majors address the dose challenge with their newest solutions. Ü GE Healthcare’s High-Definition (HD) CT technologies employ iterative reconstruction to extract additional image clarity, suppress noise and allow reduced dose. Ü Philips Healthcare’s Brilliance iCT scanner employs a new Eclipse collimator that The IT Angle CT’s newest crop certainly yield exquisite images, but how do the scanners impact storage and network capacity? There’s good news here. The IT impact is not as bad as one might think, says Pedro Diaz, PhD, vice chair of imaging and informatics at MetroHealth in Cleveland, Ohio, an early adopter of Philips Healthcare’s Brilliance iCT scanner. Bread-and-butter scans like chest, abdomen and pelvis protocols comprise 90 percent of the CT business at MetroHealth; the number of slices for these studies is the same on the 256-slice system as it is on 64- and 16slice scanners. The difference, says Diaz, is the iCT acquires the 300 slices faster and with better spatial resolution. On the other hand, emerging applications such as brain perfusion imaging and cardiac and cardiovascular scans can generate 10,000 slices, which does represent an IT challenge. Still, Diaz waxes positive. Storage is ever-cheaper, and sites need not save every acquired slice. HealthImaging.com eliminates all wasted radiation, and a step-and-shoot cardiac protocol uses one-third of the conventional radiation dose by imaging the coronaries during a single phase of the heart. Ü Siemens Medical Solutions Somatom Definition AS incorporates Adaptive Dose Shield, which dynamically blocks unnecessary dose before and after the spiral scan, ensuring the patient receives a clinically relevant dose only. Ü Toshiba America Medical Systems AquilionONE slashes scan time to 0.5 second; the shorter exposure minimizes radiation dose to the patient. quately answer nearly all routine clinical applications in body imaging including pulmonary embolism detection and fullbody trauma scans. Sixty-four slice scanners can be used for body imaging, but the additional slices add minimal clinical value to body scans, says Schoepf. In fact, in some cases like peripheral runoff studies and acute trauma scans, techs must curb 64slice scanner speed because the scan outruns the bolus. But when it comes to cardiac imaging, 64-slice systems are a valuable clinical and operational asset. “The heart and coronary arteries are minute and fast-moving targets. Successful imaging solely depends on tem16 Health Imaging & IT | January 2008 poral resolution,” explains Schoepf. With a single detector row, temporal resolution is a function of the single row; however, the addition of a second detector row improves temporal resolution by a magnitude of two. “[By improving temporal resolution] Definition DS expands cardiac imaging applications,” says Schoepf. Radiology needs to move away from rigid slice numbers as the sole determinant of a CT scanner’s utility and consider factors such as overall, versatility and usefulness of a system, says Schoepf. Definition AS fits the new niche by enabling sites to adapt to changing and emerging clinical needs. For example, the system fits in an 18m2 space, http://HealthImaging.com

Table of Contents Feed for the Digital Edition of Health Imaging & IT - January 2008

Health Imaging & IT Table of Contents On the Web The Enterprise: Is More Better? News Update A Look Inside Next-Generation Multidetector CT Convention Spotlight: RSNA in Review RIS/PACS in the Imaging Center Sweden: A Study in Mammography Excellence The Votes are in: Yea for Speech in U.S. Capital & Beyond Subspecialty Reading Services: Quality Reads, Peace of Mind, 24/7 Enterprise Lung CAD Eases Workflow Advertisers Index Company Index Coming Soon Stat Sheet

Health Imaging & IT - January 2008

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