Advertisement
(Logo: http://www.newscom.com/cgi-bin/prnh/20070904/SIEMENSLOGO)
Siemens will present its new SOMATOM Definition Flash CT scanner at the94th Scientific Assembly and Annual Meeting of the Radiological Society ofNorth America (RSNA) from November 30 to December 5 at McCormick Place (Booth#922, East Building/Lakeside Center, Hall D). This new generation of dual-source CT scanners, featuring two X-ray tubes and two detectors, will providea genuine innovation boost to dual-source technology. The enormous speed ofthe SOMATOM Definition Flash offers decisive advantages, especially regardingexaminations of moving structures, such as the thorax and the heart. Thegantry (i.e., the X-ray detector system surrounding the bore) rotates aboutits own axis in just 0.28 s. It is this extraordinary rotational speed thatenables a scan speed never before attained in CT (i.e., up to 43 cm persecond) and temporal resolution of 75 milliseconds. The patient is movedthrough the CT tube more than twice as fast as with any conventional system.At the same time, scans acquired with the SOMATOM Definition Flash require amuch lower radiation dose than conventional scans. While the average effectivedose for a heart CT scanner ranges from 8 mSv to 40 mSv, the new Siemens CTscanner gets by with less than 1 mSv. In comparison: The X-ray radiation thateveryone is exposed to each year from natural sources amounts to 2 mSv to 5mSv. The dose values of the new Siemens CT scanner, thus lie far below thoseof an intracardiac catheter examination, thus opening up possibilities forusing CT scanners for routine cardiological examinations.
Advertisement
Dr. Sami Atiya, chief executive officer of Computed Tomography at SiemensHealthcare said: "The SOMATOM Definition Flash is not only the world's fastestCT scanner, but also the one with the lowest radiation exposure. Siemens hasalways given top priority to radiation dose reduction in the course of CTdevelopment. And we are proud that our company has once again set a newstandard in this regard."
Thorax scan in the subsecond range: Breath holds no longer required
Due to the high scanning speed, it is now possible to acquire scans of thethorax, the heart or both at the same time in fractions of a second. Forexample, thorax examinations now only require a scan time of 0.6 seconds. As aresult, patients no longer have to hold their breath during the scan. Thisoffers considerable advantages, especially in cases involving the elderly,children, emergency, and ICU patients.
It is also possible to perform whole-body scans extremely fast: Forexample, a person with a height of 6 feet 6 inches can be scanned in less than4.7 seconds. Until now, such whole-body examinations took more than 10 minutesto perform from patient preparation to diagnosis. With the SOMATOM DefinitionFlash, this process is completed in just a few minutes. This represents anadvantage, especially for emergency medicine since, until now, physiciansoften had to forego this examination method due to time pressure. Furthermore,it is no longer necessary to sedate children prior to the examination, sincethey no longer have to remain still. The high scanning speed also makes itpossible to cover large areas measuring up to 48 cm with 4D imaging (3D plustime). The areas scannable using conventional systems are limited to a maximumof 16 cm due to the detector size involved.
Flexible cardiac examinations with a minimum radiation dose
A scan of the entire heart can be performed in only 250 milliseconds,which is less than half a heart beat. In addition, it is possible forphysicians to reliably display a heart with a fast pulse or an irregular heartbeat without using beta blockers, thus simplifying the workflow and yieldingclinical and financial advantages. Owing to its high scanning speed, theSOMATOM Definition Flash also features new possibilities for performing CTexaminations of the heart in the sub-mSv range. This represents a much lowerradiation dose than is obtainable with conventional systems, which requiredoses ranging from 8 mSv to more than 40 mSv. For the first time ever, theheart can thus be examined at a radiation exposure level that is three timeslower than the background radiation a person naturally absorbs in a year. TheSOMATOM Definition Flash is the only CT scanner on the market that enables theuse of noninvasive cardiological diagnostic techniques as routine applicationsat the lowest possible radiation exposure levels.
Double contrast in routine daily work
The second generation of Dual Energy imaging will introduce a new imagingquality. The contrast in CT scans will be increased without having to applythe higher radiation dose previously required. This is achieved via a new,selective photon shield which blocks unnecessary parts of the energy spectrum.It thereby provides improved separation of the two simultaneous scans with lowand high photon energy, without causing a higher radiation exposure than wouldresult from an individual, conventional CT examination with only one energysource. Thus, the SOMATOM Definition Flash can always provide a doublecontrast which, for the first time ever, can also be used to classify thechemical composition of tissues via a CT scan in routine daily work.Subsequently, it could also be used to reconstruct unenhanced CT imageswithout contrast media not having to perform an additional examination.
Dose protection for radiation-sensitive organs
Another technical development for keeping the patient's radiation exposureas low as possible is the X-CARE application. For the first time ever, thisapplication selectively reduces the radiation exposure of dose-sensitiveanatomical regions, such as the female breast. This is done by switching theX-ray tube assemblies off during the rotation phase in which the anatomicalregions concerned are most directly exposed to radiation. In this way, it ispossible to reduce the radiation exposure of individual anatomical regions byup to 40 percent. Furthermore, an adaptive dose shield blocks irrelevantprespiral and postspiral radiation with dynamic diaphragms, thus ensuring thatonly a minimum and clinically essential radiation exposure occurs. Thisenables an additional 25 percent reduction of the dose required for routineexaminations. The CARE Dose4D software, which analyzes the individualcross-sectional anatomy in real time and adapts the emitted X-ray doseaccordingly, also helps to reduce radiation exposure.
The Siemens Healthcare Sector is one of the world's largest suppliers tothe healthcare industry. The company is a renowned medical solutions providerwith core competence and innovative strength in diagnostic and therapeutictechnologies as well as in knowledge engineering, including informationtechnology and system integration. With its laboratory diagnosticsacquisitions, Siemens Healthcare is the first integrated healthcare company,bringing together imaging and lab diagnostics, therapy, and healthcareinformation technology solutions, supplemented by consulting and supportservices. Siemens Healthcare delivers solutions across the entire continuum ofcare - from prevention and early detection, to diagnosis, therapy and care.Additionally, Siemens Healthcare is the global market leader in innovativehearing instruments. The company employs around 49,000 people worldwide andoperates in 130 countries. In the fiscal year 2008 (Sept. 30), SiemensHealthcare reported sales of euro 11.2 billion, orders of euro 11.8 billion,and Sector profit of euro 1.2 billion. Further information can be found byvisiting http://www.siemens.com/healthcare.
SOURCE Siemens Healthcare
