New use for barley

Photoacoustic computed tomography (PACT) is an emerging alternative to X-rays, MRIs or ultrasounds. The systems can provide high-resolution imaging of optical absorption in deep tissue, and various preclinical and clinical applications of the technique have been demonstrated, including functional brain imaging, small-animal whole-body imaging, breast cancer screening, guidance of lymph node biopsies, and it can also be used to help diagnose swallowing disorders.

Patients drink or are injected with a contrast agent — often newly developed nanoparticles made of metals, polymers and other materials. A laser strikes the nanoparticles, generating pressure waves that can provide nuanced and real-time views inside the body.

One drawback to contrast-enhanced PACT is the often lengthy and expensive regulatory process for new contrast agents.

Researchers at the University at Buffalo bought more than 200 types of tea, chocolate, herbs and other foodstuffs in an attempt to find an edible contrast agent.

They found that a roasted version of barley, when struck by a common laser beam, can illuminate the throat and the gastrointestinal track. The real benefit is that as many human diets already include barley, it can be fast-tracked for medical use.

The researchers focused on dark foods and beverages because the darker the colour, the more the foodstuff will absorb wavelengths from the laser and, theoretically, produce a clearer image.

Roasted barley, a grain used to produce beer, bread and other products, provided the best results. Researchers were able to detect individual particles of it through 3.5 cm of chicken breast tissue, as well as through human hands.

Roasted barley tea — a drink common in Japan, Korea and China — was detectable through 2.5 cm of chicken breast. It worked in human subjects as well, providing visualisations inside the human throat when swallowing.

In addition to swallowing imaging, researchers say roasted barley could potentially be used to diagnose gastrointestinal tract disorders.

Image credit: ©stock.adobe.com/au/Gina Sanders