Swallowing, the natural process that’s required when eating and drinking, is a natural part of life. However, not being able to swallow is a condition called dysphagia and it can be an indication of cancer, Alzheimer’s disease and neck injuries. To diagnose dysphagia, doctors will often ask patients to drink a thick, chalky liquid called barium. Doctors then use X-rays, MRIs or ultrasounds to look inside the upper digestive system. But these techniques are limited by high costs, safety issues and a lack of adequate contrast. Another emerging technique used is Photoacoustic computed tomography (PACT), where patients are injected nanoparticles made of metals, polymers and other materials and doctors get real-time views of inside the body. But this technique is often lengthy and expensive, which led scientists from the University of Buffalo to look for edible alternatives.
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The researchers screened 200 types of ingestible foodstuff samples for photoacoustic contrast with 1064 nm pulse laser excitation. They focussed on dark foods and beverages such as tea, chocolate and herbs — as the darker the colour, the more the foodstuff will absorb wavelengths from the laser and thus produce a clearer image. They identified roasted barley — a grain used to produce beer, bread and other products — as a promising candidate. They further screened 20 brands of roasted barley to identify the strongest contrast. The researchers were able to detect barley particles through 3.5 cm of chicken breast tissue as well as through the hands of healthy volunteers. A single grain of roasted barley was detected in a field on non-roasted barley with PACT but not ultrasound imaging. The researchers found that roasted barley tea was detectable through 2.5 cm of chicken breast tissue and when administered to human volunteers, photoacoustic imaging showed visualisations inside the throat when swallowing. In addition to swallowing imaging, researchers say roasted barley could potentially be used to diagnose gastrointestinal tract disorders.
This discovery could help improve the diagnosis of swallowing disorders and gut problems. Barley is considered a safe food to consume for most people, making the roasted version of the grain fit for medical use and for photoacoustic contrast imaging.
Source: Biomaterials
