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bioRxiv · 10.1101/2023.06.27.545971

Photoacoustic Imaging as a Novel Non-Invasive Biomarker to Assess Intestinal Tissue Oxygenation and Motility in Neonatal Rats

Weis, V. G.·Cruz-Diaz, N.·Rauh, J. L.·Ellison, M. A.·Yamaleyeva, L. M.·Welch, C. D.·Zeller, K. A.·Weis, J. A.
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Abstract

BackgroundWithin the premature infant intestine, oxygenation and motility play key physiological roles in healthy development and disease such as necrotizing enterocolitis. To date, there are limited techniques to reliably assess these physiological functions that are also clinically feasible for critically ill infants. To address this clinical need, we hypothesized that photoacoustic imaging (PAI) can provide non-invasive assessment of intestinal tissue oxygenation and motility to characterize intestinal physiology and health. MethodsUltrasound and photoacoustic images were acquired in 2-day and 4-day old neonatal rats. For PAI assessment of intestinal tissue oxygenation, an inspired gas challenge was performed using hypoxic, normoxic, and hyperoxic inspired oxygen (FiO2). For intestinal motility, oral administration of ICG contrast agent was used to compare control animals to an experimental model of loperamide-induced intestinal motility inhibition. ResultsPAI demonstrated progressive increases in oxygen saturation (sO2) as FiO2 increased, while the pattern of oxygen localization remained relatively consistent in both 2-day and 4-day old neonatal rats. Analysis of intraluminal ICG contrast enhanced PAI images yielded a map of the motility index in control and loperamide treated rats. From PAI analysis, loperamide significantly inhibited intestinal motility, with a 32.6% decrease in intestinal motility index scores in 4-day old rats. ConclusionThese data establish the feasibility and application of PAI to non-invasively and quantitatively measure intestinal tissue oxygenation and motility. This proof-of-concept study is an important first step in developing and optimizing photoacoustic imaging to provide valuable insight into intestinal health and disease to improve the care of premature infants. HighlightsO_LIIntestinal tissue oxygenation and intestinal motility are important biomarkers of intestinal physiology in health and disease of premature infants. C_LIO_LIThis proof-of-concept preclinical rat study is the first to report application of photoacoustic imaging for the neonatal intestine. C_LIO_LIPhotoacoustic imaging is demonstrated as a promising non-invasive diagnostic imaging method for quantifying intestinal tissue oxygenation and intestinal motility in premature infants. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=145 HEIGHT=200 SRC="FIGDIR/small/545971v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@585d0forg.highwire.dtl.DTLVardef@145a2bcorg.highwire.dtl.DTLVardef@bf0c46org.highwire.dtl.DTLVardef@bed354_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Weis, V. G., Cruz-Diaz, N., Rauh, J. L., Ellison, M. A., Yamaleyeva, L. M., Welch, C. D., Zeller, K. A., Weis, J. A.. 2023-06-27. Photoacoustic Imaging as a Novel Non-Invasive Biomarker to Assess Intestinal Tissue Oxygenation and Motility in Neonatal Rats. https://doi.org/10.1101/2023.06.27.545971

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