National research institute selects GE ultrasound machine

GE Medical Systems will provide its Logiq 700 Pro ultrasound scanners to six institutions participating in a 10-year cardiovascular study sponsored by the National Heart, Lung, and Blood Institute.

In order to sell seven ultrasound scanners‹one each to five institutions and two to the sixth‹GE competed successfully against five other major vendors. The equipment was chosen primarily for its image quality, according to Dr. Joseph F. Polak, a coinvestigator on the study.

"The images were just better," said Polak, an associate professor of radiology at Harvard Medical School. "We evaluated them as impartially as we could."

During the equipment evaluation, which took place in December 1999, an experienced sonographer scanned two volunteers during a two-day session at the New England Medical Center Ultrasound Reading Center in Boston. Scans were then digitized and further evaluated.

As part of the process, images were sent via the Internet to all six research sites for evaluation and scoring. Reviewers did not know which equipment produced which data, according to Jeff Peiffer, GE's Americas marketing manager for ultrasound.

Investigators will use the Logiq 700 to measure wall thickening of the carotid artery, one sign of risk for stroke. The goal is to measure early atherosclerotic changes, Polak said.

"Measurement of coronary artery calcification is currently used as a screening test to identify people at risk," Polak said. "This measurement is basically the same as detecting a rock in the coronary artery. If we can learn to identify (high-risk people) at earlier stages of disease, we will be better able to keep them from getting into trouble."

The researchers will observe participants with subclinical artery and heart disease, hoping to examine specific factors that predict progression to clinical disease. The American Heart Association acknowledges that carotid wall thickening is by itself an important predictor of stroke and heart attack.

Researchers will employ other technologies, including CT and MRI, for evaluating risk factors. The study also involves blood tests, measurement of arterial waveforms, and questionnaires to assess demographics and psychosocial factors.

"This is an epidemiological study, and as such it requires as much quantitative data as we can get," Polak said. "Our ultimate goal is to understand key factors that lead to heart attack and stroke and learn to use these factors to identify people at risk."

By the end of the study, about 6500 men and women aged 45 to 84 from varied ethnic backgrounds will have been examined. The projected breakdown is 40% Caucasian, 30% African American, 20% Hispanic, and 10% Asian.

Successful measuring of carotid wall thickening depends on high-resolution ultrasound images and specialized measurement software, according to Polak. The process begins by getting the best quality images possible, he said.

"If you don't, you have the phenomenon of Œgarbage in, garbage out,'" he said.

Participating in the study are the University of California, Los Angeles; Johns Hopkins University; the University of Minnesota; Northwestern University Medical School; Wake Forest University; and Columbia University.

ltrasound images acquired at the six sites will be sent for reading to the New England Medical Center. There, specially trained readers will use workstations and proprietary software to take the necessary measurements. Each of the six research sites will use systems with matching configurations to ensure the compatibility of data.