Dual-modality ultrasound/photoacoustic tomography for mapping tissue oxygen saturation distribution in intestinal strangulation

The strangulation of intestinal obstruction (IO) presents challenges in the assessment of disease progression and surgical decision-making. Intraoperatively, an accurate evaluation of the status of the IO is critical for determining the extent of surgical resection. Dual-modality ultrasound/photoacoustic tomography (US/PAT) imaging has the potential to provide spatially resolved tissue oxygen saturation (SO₂), serving as a valuable marker for IO diagnosis. In this study, US/PAT was utilized for imaging rat models of IO, with the data used for reconstruction, statistical analysis, and distribution evaluation. Results showed that SO₂ decreased with increasing strangulation severity. Notably, the kurtosis and skewness of the SO₂ distribution outperformed SO₂ itself in diagnosis, as they more effectively capture the heterogeneity of SO₂ distribution. Kurtosis reflects distribution concentration, while skewness measures asymmetry, both achieving areas under the receiver operating characteristic curve (AUROC) of 0.969. In conclusion, US/PAT offers a rapid and convenient method for assessing strangulation in IO.