Transrectal Absorber Guide Raster‐Scanning Optoacoustic Mesoscopy for Label‐Free In Vivo Assessment of Colitis

• Published in: Advanced science 2023-06, Vol.10 (18), p.e2300564-n/a
• Main Authors: Buehler, Adrian, Brown, Emma, Paulus, Lars‐Philip, Eckstein, Markus, Thoma, Oana‐Maria, Oraiopoulou, Mariam‐Eleni, Rother, Ulrich, Hoerning, André, Hartmann, Arndt, Neurath, Markus F., Woelfle, Joachim, Friedrich, Oliver, Waldner, Maximilian J., Knieling, Ferdinand, Bohndiek, Sarah E., Regensburger, Adrian P.
• Format: Article
• Language: English
• Subjects: Animals; Biomarkers; Colitis - diagnostic imaging; Colon; dextran sodium sulfate induced colitis; Disease; Endoscopy; Histopathology; Humans; Inflammatory bowel disease; Inflammatory Bowel Diseases - diagnostic imaging; Mice; murine acute colitis; Nitrates; Optical Imaging; optoacoustic imaging; photoacoustic imaging; Photoacoustic Techniques - methods; rasterscanning optoacoustic mesoscopy; Remission (Medicine); Skin; Visualization
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202300564

Optoacoustic imaging (OAI) enables microscale imaging of endogenous chromophores such as hemoglobin at significantly higher penetration depths compared to other optical imaging technologies. Raster‐scanning optoacoustic mesoscopy (RSOM) has recently been shown to identify superficial microvascular changes associated with human skin pathologies. In animal models, the imaging depth afforded by RSOM can enable entirely new capabilities for noninvasive imaging of vascular structures in the gastrointestinal tract, but exact localization of intra‐abdominal organs is still elusive. Herein the development and application of a novel transrectal absorber guide for RSOM (TAG‐RSOM) is presented to enable accurate transabdominal localization and assessment of colonic vascular networks in vivo. The potential of TAG‐RSOM is demonstrated through application during mild and severe acute colitis in mice. TAG‐RSOM enables visualization of transmural vascular networks, with changes in colon wall thickness, blood volume, and OAI signal intensities corresponding to colitis‐associated inflammatory changes. These findings suggest TAG‐RSOM can provide a novel monitoring tool in preclinical IBD models, refining animal procedures and underlines the capabilities of such technologies to address inflammatory bowel diseases in humans. Optoacoustic imaging uses laser light excitation and ultrasound detection for deep tissue imaging. Transrectal absorber guide raster‐scanning optoacoustic mesoscopy (TAG‐RSOM) is created to achieve microscopic decoding of transmural vascular networks during inflammation in murine colitis in vivo. These findings underline the capabilities of optoacoustic technologies to address inflammatory bowel diseases in humans.