The study 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, according to the researchers from Duke University's Pratt School of Engineering. They say it might also 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 Duke 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," said Trahey, professor of biomedical engineering, radiology and medical physics at Duke.
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, Trahey said. "If borne out in further studies, that discriminating ability suggests that ARFI may be useful in guiding treatment decisions."
"All current imaging methods — including CT, MRI and ultrasound — have mediocre performance in the detection of early liver cancers," he added. "There is a potential role for ARFI because it is low cost and can be built on conventional ultrasound machines."
In the new study, the researchers captured ARFI images of 12 tumors in nine patients, including seven liver and two kidney tumors, and compared them to traditional ultrasound. The ARFI pictures showed greater contrast than standard ultrasound, providing clearer definition of the edges of cancerous masses.
MEDICA.de; Source: Duke University