Contrast‐Enhanced Multispectral Optoacoustic Tomography for Functional Assessment of the Gastrointestinal Tract

Real‐time imaging and functional assessment of the intestinal tract and its transit pose a significant challenge to conventional clinical diagnostic methods. Multispectral optoacoustic tomography (MSOT), a molecular‐sensitive imaging technology, offers the potential to visualize endogenous and exogenous chromophores in deep tissue. Herein, a novel approach using the orally administered clinical‐approved fluorescent dye indocyanine green (ICG) for bedside, non‐ionizing evaluation of gastrointestinal passage is presented. The authors are able to show the detectability and stability of ICG in phantom experiments. Furthermore, ten healthy subjects underwent MSOT imaging at multiple time points over eight hours after ingestion of a standardized meal with and without ICG. ICG signals can be visualized and quantified in different intestinal segments, while its excretion is confirmed by fluorescent imaging of stool samples. These findings indicate that contrast‐enhanced MSOT (CE‐MSOT) provides a translatable real‐time imaging approach for functional assessment of the gastrointestinal tract. Multispectral optoacoustic tomography (MSOT), a non‐invasive, molecular‐sensitive imaging technology, allows visualization and quantification of chromophores in deep tissue. In a translational approach, transabdominal contrast‐enhanced (CE) MSOT is performed after the oral intake of indocyanine green (ICG) for real‐time assessment of the gastrointestinal transit. CE‐MSOT offers the capabilities for immediate clinical translation to visualize numerous gastrointestinal pathologies.