High-energy ultrasound sharpens tumor view.

• Position: Liver Disease - Acoustic Radiation Force Impulse - Clinical report

A high-energy form of ultrasound imaging developed by researchers at Duke University's Pratt School of Engineering, Durham, N.C., produces pictures of liver tumors that are better than those made with traditional ultrasound, according to results of a clinical study, which suggests that the imaging method known as Acoustic Radiation Force Impulse (ARFI) ultrasound might offer a new tool for screening patients at increased risk for liver cancers. It also might play a useful role in guiding biopsy procedures and minimally invasive therapies aimed at destroying cancerous tissues found deep in the abdomen.

First developed six years ago by biomedical engineers Gregg Trahey and Kathy Nightingale, ARFI uses high-energy sound waves to push on tissues like sonic fingers. A tracking beam then captures the movement of the tissue, providing a measure of its elasticity or stiffness. "To our knowledge, these are the first images of abdominal malignancies in humans that show tissue elasticity," asserts Trahey, professor of biomedical engineering, radiology, and medical physics.

The preliminary findings have led Siemens Medical Solutions, Tarrytown, N.Y., to pursue a product prototype that will combine traditional ultrasound with ARFI.

In general, primary liver cancers are soft, while those that have spread from other organs are hard. ARFI may be able to tell the difference between hard and soft tumors...