New imaging agent provides better picture of the gut

Researchers has developed a new safe, noninvasive method for assessing the function and properties of the gastrointestinal (GI) in real time that could lead to better diagnosis and treatment of gut diseases.

Illnesses such as small bowel bacterial overgrowth, irritable bowel syndrome and inflammatory bowel disease all occur in the intestine and can lead to serious side effects in patients with diseases such as diabetes and Parkinson's. Until now, there hasn't been a good way to functionally image the intestine.

However, researchers demonstrated that through a complementary approach using photo-acoustic imaging and positron emission tomography (PET), they have created a multi-modal functional imaging agent that could be used to perform noninvasive functional imaging of the intestine in real time.

Weibo Cai from the University of Wisconsin-Madison — worked with Jonathan Lovell, from the State University of New York (SUNY) at Buffalo, and Chulhong Kim, from the Pohang University of Science and Technology in South Korea.

The team developed a family of nanoparticles that can provide good optical contrast for imaging — yet avoid absorption into the body and withstand the harsh conditions of the stomach and intestine.

Currently, patients drink a chalky liquid called barium and technicians view the intestine through X-rays and ultrasound. These methods, however, have many limitations, including accessibility and the possibility of radiation exposure.

The researchers' nanoparticles contain bright dyes. Patients still will drink a liquid, but it will contain the nanoparticles and allow an imaging technician to noninvasively view the illuminated intestine with photo-acoustic imaging. "We can actually see the movement of the intestine in real time," Lovell said.

Cai and Lovell worked collaboratively to use two imaging techniques. While photo-acoustic techniques yield high-definition images, PET imaging can penetrate deeper and image the entire body.

Combining the two delivers the most information possible: high-definition images, images deep inside the body and a view of the intestine in relation to the entire body.

So far, the researchers have conducted successful test trials in mice and are hoping to move to human trials soon. The research was published in the journal Nature Nanotechnology.