Photoacoustic imaging, Contrast-enhanced ultrasound, Acute intussusception, Oxygen saturation, Ischemia/hypoxia injury, Intestinal necrosis, Physics, QC1-999, Acoustics. Sound, QC221-246, Optics. Light, QC350-467

Acute intussusception is a pediatric abdominal emergency that requires immediate diagnosis and treatment. However, accurately identifying bowel necrosis non-invasively remains challenging with conventional sonography. In our study, we investigated the potential of photoacoustic imaging (PAI) as an innovative method for assessing ischemia/hypoxia injury and intestinal necrosis in cases of acute intussusception. Using PAI, we measured intestinal oxygen saturation (sO2) levels and total hemoglobin (HbT) in various models of acute intussusception at different time points. Additionally, we evaluated blood supply and ischemia/hypoxia injury using color Doppler flow imaging (CDFI) and contrast-enhanced ultrasound (CEUS). Based on histopathological results, intestinal sO₂ measured by PAI demonstrated optimal diagnostic performance for both ischemia/hypoxia injury and intestinal necrosis, with AUC values of 0.997 and 0.982, respectively, while CDFI and CEUS showed relatively high diagnostic performance for both ischemia/hypoxia injury and intestinal necrosis. In conclusion, PAI represents a promising, non-invasive imaging modality for assessing acute intussusception.