Study finds roasted barley a superior contrast agent for imaging swallowing disorders

When researchers bought more than 200 types of tea, chocolate, herbs and other items, they weren’t planning meals for the week. Instead, the team was searching for a contrast agent for imaging patients with swallowing disorders—and they landed on barley.

A team of 12 from the University at Buffalo (UB) in New York detailed how a roasted version of the grain can serve as a contrast agent for dysphagia, in research published in the journal Biomaterials.

"It's really incredible. Here you have this common grain—it has been grown all over the world for thousands of years, and used to make tea, bread, beer—and we're just now finding another use for it as a contrast agent for medical imaging," said Jun Xia, PhD, and assistant professor with UB’s Department of Biomedical Engineering, in a news release.

Xia and colleagues screened 200 different foodstuff samples to determine which paired best with photoacoustic computed tomography (PACT)—an emerging modality used on dysphagia patients. After determining barley the winner, the team tested 20 roasted barley brands to determine which provided the best contrast.

Individual roasted barley particles could be detected through 3.5 cm of chicken-breast tissue and through the hand of a human volunteer. When using PACT, a single grain could be seen in a field of hundreds of non-roasted particles.

When fed to a mouse model, photoacoustic imaging could visualize the gut and peristalsis. Xi et al. noted when barley tea was given to humans, PACT imaging could show the swallowing dynamics of volunteers.

The commonly ingested product would provide a better alternative to the traditional standard barium, which is a thick, chalky liquid used in x-ray, MRI and ultrasound to visualize the throat. Similarly, in PACT, imaging patients are required to drink or are injected with a contrast agent often made of inorganic materials, authors noted.

“Roasted barley represents an edible foodstuff that should be considered for photoacoustic contrast imaging of swallowing and gut processes, with immediate potential for clinical translation,” Xia and colleagues concluded in the study.