The fastest computed tomography scanner, Somatom Definition – faster than a heartbeat

(Siemens) With the Somatom Definition, Siemens has developed the world’s first computed tomography (CT) system in which the patient is scanned with two X-ray sources simultaneously – a remarkable technological breakthrough. It can produce images of the inside of the body at unprecedented speed. Even when examining patients with high or irregular heart rates, the Somatom Definition produces images of the highest quality and extremely accurate detail – while exposing the patient to only half the radiation dose required by earlier systems. This huge advance in diagnostic imaging is based on the Straton X-ray tube, which was likewise nominated for the German Future Prize 2005. The new system was recently presented to a professional audience at the RSNA (Radiological Society of North America) congress, the largest international radiology meeting.

Coronary artery diseases are the number-one cause of premature death in Germany, accounting for almost 150,000 deaths each year. Early diagnosis could save many of these patients’ lives. The high speed and accuracy of the new Siemens computed tomography system will enable faster and more reliable diagnostics to be performed on coronary vessels, without the need for surgical intervention. For the first time, it will now be possible to examine every patient, regardless of individual factors such as corpulence, general condition or heart rate, and obtain the same high quality of images. For instance, some patients previously had to be given medication (beta blockers) to slow their heart rate before a scan could be made of their otherwise rapidly or irregularly beating heart.

The new CT system visualizes the finest anatomical structures, producing unusually sharp images of unprecedented clarity while at the same time reducing radiation exposure by up to 50%. “Siemens’ newest CT system provides very valuable clinical information on patients arriving in our department with acute chest pain and suspected coronary artery disease,” says Dr. Stephan Achenbach, associate professor of cardiology at the University of Erlangen.

As well as its uses in the diagnosis of cardiovascular diseases, where it heralds a new era, the technology is suitable for many other types of examination, also in other branches of medicine such as oncology, neurology or acute care. Scans can be performed on acute care patients very quickly, for instance, even those who are unusually tall or adipose.

Owing to its two X-ray tubes, the system is capable of performing scans using two different energy levels simultaneously, allowing the physician to obtain a wider range of information from inside the patient’s body. Especially in the case of accident victims, when the physician needs to be able to assess the extent of possible internal injuries as quickly and in as much detail as possible, this approach furnishes far more information in much less time. With a single scan, it is possible to visualize tissue and fluids and at the same time differentiate blood vessels, bone and internal organs.

"The fact that the top healthcare institutions across the world have responded so quickly to the new system, and can hardly wait to install it in their institutes, confirms that Siemens continues to be the innovation leader in diagnostic technology,” says Klaus Kleinfeld, President and CEO of Siemens AG. "Siemens is committed to being the pacesetter for healthcare innovation, and we mean to continue to invest in research and development that will ultimately fulfill this promise."

The first Somatom Definition was installed at the University of Erlangen in October 2005 and is being used for technical and clinical research as well as regular patient care. "We expect that the Somatom Definition will have a significant role in even the most demanding environments, such as emergency departments,” says Professor Werner Bautz, who heads the Department of Diagnostic Radiology at Erlangen University Hospital.

The next systems to go into use will be installed in early 2006 at the Großhadern Clinic in Munich, at the Mayo Clinic in Rochester, Minnesota, at the Cleveland Clinic Foundation in Ohio, and at the New York University Medical Center.

The Somatom Definition is faster than any existing CT technology. This dual-source system uses two X-ray sources and two detectors at the same time. With a rotation time of 0.33 seconds, ECG-synchronized imaging can be performed with a temporal resolution of 83 ms, independent of the heart rate. The scanner has a gantry bore of 78 centimeters, much wider than other CT systems, enabling even obese patients to be examined easily.

"Siemens has long been committed to creating products that will shape the future of healthcare. With the Somatom Definition, we are truly redefining what CT can do and are setting a new benchmark for the industry to follow,” states Professor Erich R. Reinhardt, Member of the Managing Board of Siemens AG and President and CEO of Siemens Medical Solutions. "CT already has a tremendous impact on detecting disease. The Siemens Somatom Definition will allow physicians to utilize CT technology in new areas of research, bring the benefits of CT to more patients, and enable physicians to diagnose disease earlier and more cost-effectively."