SonoSite Initiates Multi-Center Cardiovascular Research Study; Ultrasound Study to Assess Carotid Intima Media Thickness in an Office Setting; 525 Patients to Be Enrolled at Seven Medical Centers.

DALLAS -- SonoSite, Inc. (Nasdaq:SONO), the world leader in hand-carried ultrasound, announced today at the 2005 American Heart Association (AHA) Scientific Sessions that it is initiating a multi-center study to determine whether the addition of an ultrasound examination evaluating carotid artery wall thickness (CIMT), performed in the office setting, will provide a more effective tool for risk assessment and prevention of cardiovascular disease than current clinical methods alone.

Over 20 years of clinical research has shown that the thickness (T) of the two innermost layers of the carotid artery wall, the intima (I) and media (M), begins to increase before plaque is evident within the vessel. This increased wall thickness is associated with an increased risk of cardiovascular disease, the leading cause of mortality and disability in the United States today.

"IMT addresses the need to identify those patients who are asymptomatic or have limited risk factors, such as moderately elevated cholesterol levels, who may be at greater than apparent risk for a cardiovascular event," explains James H. Stein, MD, Associate Professor, University of Wisconsin Medical School. Dr. Stein is the Director of the University of Wisconsin Atherosclerosis Imaging Research Program and principal investigator of the study.

"Although IMT is recognized as a valuable adjunct in cardiovascular risk stratification, it primarily has been used as a research tool," Dr. Stein stated. "With the advent of high-resolution, hand-carried ultrasound systems and software algorithms, it is more practical to incorporate this tool into clinical practice. Through this trial, we hope to determine if health care professionals can accurately perform this exam in the office setting and thereby detect cardiovascular disease before it causes a heart attack or stroke."

Until recently, measuring cholesterol or C-Reactive Protein (CRP), an indicator of blood vessel inflammation, have been among the few options in evaluating the risk of cardiovascular disease. However, clinical studies suggest that IMT may be more predictive and specific to cardiovascular risk than either CRP or traditional lipid profile alone, making IMT an important tool for identifying patients at increased risk for cardiovascular disease.

Called "OPACA" for Office Practice Assessment of Carotid Atherosclerosis using Handheld Ultrasound Study, investigators plan to enroll 525 patients at medical centers located in Philadelphia; Minneapolis; New York City; Chicago; Boise, Idaho; and Rochester, Minnesota. Data collection and analysis is expected to be completed by June of 2006. The study will use SonoSite's MicroMaxx(TM) system with embedded SonoCalc(TM) software, a hand-carried ultrasound system weighing just under eight pounds, and a L38 linear array transducer. The noninvasive ultrasound examination can be completed in approximately 15 minutes and does not expose a patient to ionizing radiation.

"Moving IMT out of the research lab and into the physician's office is part of our long-term vision for incorporating ultrasound into the physical examination," said Kevin M. Goodwin, SonoSite President and CEO. "We are pleased to join with Dr. Stein and the other study investigators in their efforts to find practical and cost-effective methods for preventing and lowering the risk of heart disease."

Introduced a year ago at the 2004 AHA Scientific Sessions, SonoSite's patented SonoCalc(TM) IMT automated edge detection technology provides physicians with the ability to analyze the IMT of a patient's carotid artery. IMT has been used as an indicator of efficacy in the development of several statin and antihypertensive drugs and is widely recognized as a surrogate marker for identifying and evaluating the vascular disease and its progression, both indicators of heart disease and stroke.

SonoSite will be offering IMT screenings in Booth 533 during the AHA Scientific Sessions from November 13-16 being held at the Dallas Convention Center. For more information on the OPACA trial, contact Hal Widlansky, Global Director, Cardiovascular at 425-951-1206.

About SonoSite

SonoSite, Inc. (www.sonosite.com) is the innovator and world leader in hand-carried ultrasound, with an installed base of more than 20,000 systems. Headquartered near Seattle, SonoSite is represented by eight subsidiaries and a global distribution network in over 75 countries. SonoSite's small, lightweight systems are expanding the use of ultrasound across the clinical spectrum by cost-effectively bringing high-performance ultrasound to the point of patient care. The company employs approximately 470 people worldwide.