Clinical Studies Demonstrate Effectiveness of Siemens 64-Slice Computed Tomography in Cardiac Care; More Than 350 SOMATOM Sensation 64 Systems Installed Worldwide.

MALVERN, Pa. -- Engaging in intensive research during the past twelve months, Siemens' clinical collaborators continue to lead the scientific community in studies focusing on the validation of multi-slice computed tomography (CT) systems in cardiac imaging. More than 80 percent of clinical research published to date on cardiac CT has involved Siemens CT technology, with three 64-slice studies published in peer-reviewed, internationally renowned medical journals. Siemens Medical Solutions SOMATOM(R) Sensation 64 CT system is the most successful 64-slice CT system with more than 350 installations worldwide. Over 40 percent of these installations include the SOMATOM Sensation Cardiac 64, which specializes in the diagnosis and treatment of cardiovascular disease.

In the published studies, results derived from 64-slice CT were compared to traditional invasive catheter angiography and intravascular ultrasound (IVUS). The authors of all the articles highlight the SOMATOM Sensation 64's excellent image quality with an isotropic spatial resolution of below 0.4 millimeter in all routine and cardiac scan modes, enabling a new level of clinical confidence. Using z-Sharp(TM) Technology and a rotation speed of 0.33 seconds, the system supplies high quantitative and qualitative diagnostic accuracy for the non-invasive assessment of coronary artery stenoses, coronary plaque composition and plaque burden in a broad spectrum of patients.

A study conducted by Leschka et al., from the University Hospital, Zurich, Switzerland(1) investigated the accuracy of the SOMATOM Sensation 64 for assessing hemodynamically significant stenoses of coronary arteries in a consecutive patient population. The SOMATOM Sensation 64's high performance allowed the examination of these patients without the use of any special medication to lower the patients' heart rate. All coronary vessels were included for evaluation and all segments could be evaluated. The authors conclude that the SOMATOM Sensation 64 provides a high diagnostic accuracy in assessing coronary artery stenosis, compared to conventional invasive angiography.

These results were confirmed by the group of Raff et al., from William Beaumont Hospital, Royal Oak, Mich.(2), by comparing the accuracy of the SOMATOM Sensation Cardiac 64 in detecting and accurately measuring coronary lesions to conventional angiography including Quantitative Coronary Analysis. The results indicate high quantitative and qualitative diagnostic accuracy of 64-slice multislice CT in a broad spectrum of patients, also including those patients who are obese and/or have heavily calcified coronary arteries.

Another research team from Klinikum Grosshadern, University of Munich(3) led by Leber et al., evaluated the accuracy of the SOMATOM Sensation 64 to detect and differentiate different types of coronary plaques, and to determine plaque burden compared to IVUS. According to the authors, the measurements of plaque and lumen area by CT correlated very well with measurements performed with IVUS.

The SOMATOM Sensation 64 incorporates Siemens proprietary z-Sharp Technology, which allows two focal points from the anode via precise deflection of the electron beam within the X-ray tube, generating two overlapping beams that pass the scan field. The double readout of the detector produces 64 slice projections down to 0.3 mm slice distance without increasing the radiation dose beyond a 16-slice CT. Further, Siemens' proprietary high-speed, ultra fast ceramic detector enables a virtually simultaneous read-out of two projections for each detector element, resulting in 64-slice acquisition. With z-Sharp Technology the system delivers optimal image quality with a routine isotropic resolution of below 0.4 millimeters, firmly establishing a new benchmark for diagnostic excellence.

With the combination of Speed4D(TM) Technology and the world's fastest gantry rotation speed of up to 0.33 seconds, the SOMATOM Sensation 64 also offers the fastest scan speed, achieving a temporal resolution of up to 83 milliseconds, and thus facilitates scanning of patients even with higher heart rates, virtually freezing the heart's motion. For the first time, this CT performance allows for the evaluation of the most common causes of acute chest pain with a single scan.

Siemens Medical Solutions of Siemens AG (NYSE:SI) with headquarters in Malvern, Pennsylvania and Erlangen, Germany, is one of the largest suppliers to the healthcare industry in the world. The company is known for bringing together innovative medical technologies, healthcare information systems, management consulting, and support services, to help customers achieve tangible, sustainable, clinical and financial outcomes. Employing approximately 31,000 people worldwide and operating in more than 120 countries, Siemens Medical Solutions reported sales of 7.07 billion EUR, orders of 8.12 billion EUR and group profit of 1.05 billion EUR for fiscal 2004. More information can be obtained by visiting http://www.usa.siemens.com/medical-pressroom.

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(1) Sebastian Leschka*, Hatem Alkadhi*, Andre Plass+, Lotus Desbiolles*, Juerg Gruenenfelder+, Borut Marincek*, and Simon Wildermuth*; Accuracy of MSCT coronary angiography with 64-slice technology: first experience. European Heart Journal, Advance Access, April 19, 2005.

*+University Hospital Zurich, Switzerland, *Department of Medical Radiology, Institute of Diagnostic Radiology, +Clinic for Cardiovascular Surgery

(2) Gilbert L. Raff*, Michael J. Gallagher*, William W. O'Neill*, James A. Goldstein*; Diagnostic Accuracy of Noninvasive Coronary Angiography Using 64-Slice Spiral Computed Tomography. Journal of the American College of Cardiology, Vol. 46, 3, July 2005

*William Beaumont Hospital, Royal Oak, MI., USA, Cardiology Division

(3) Alexander W. Leber*, Andreas Knez*, Alexander Becker*, Franz von Ziegler*, Konstantin Nikolaou+, Bernd Ohnesorge#, Maximilian Reiser+, Gerhard Steinbeck*, Christoph R. Becker+, Peter Boekstegers*; Accuracy of 64-slice CT to classify and quantify coronary plaque volumes. A comparative study with intravascular ultrasound. Journal of the American College of Cardiology, Vol. 46, 1, July 2005.

*+Klinikum Grosshadern, University of Munich, Munich, Germany, *Department of Cardiology; +Institute for Diagnostic Radiology; #Siemens Medical Solutions, Forchheim, Germany