Tiny Particles Enhance Ultrasound Images

In laboratory experiments on mice, scientists found that nano-sized particles injected into the animals improved the resulting images. This study is one of the first reports showing that ultrasound can detect these tiny particles when they are inside the body, said Thomas Rosol, a study co-author and dean of the college of veterinary medicine at Ohio State University.

The researchers injected a solution of silica nanoparticles into the tail vein of each mouse. They then anesthetized the animals and placed them on their backs on a warm imaging table.

Rosol said that Jun Liu, an assistant professor of biomedical engineering at Ohio State University, and her team are working on creating biodegradable nanoparticles. For the purposes of this study, however, the researchers wanted to use a hard substance, silica, to see if their idea would work. The strongest ultrasound signals are those produced by sound waves bounce off a hard surface. While not biodegradable, the nanoparticles used in the study were biologically inert.

The researchers took ultrasound images of the animals' livers every five minutes for 90 minutes after the injection. The nanoparticles had accumulated in the animals' livers. Another future step for this work is to label nanoparticles with a molecular road map of sorts, which would direct the particles to go to specific locations in the body.

"Given their tiny size, nobody thought it would be possible for ultrasound to detect nanoparticles," he said. It turns out that not only can ultrasound waves sense nanoparticles, but the particles can brighten the resulting image. One day, those bright spots may indicate that a few cells in the area may be on the verge of mutating and growing out of control.

"The long-term goal is to use this technology to improve our ability to identify very early cancers and other diseases," said Liu. "We ultimately want to identify disease at its cellular level, at its very earliest stage."

MEDICA.de; Source: Ohio State University