Testicular torsion diagnosis and injury assessment using photoacoustic oxygenation imaging

Testicular torsion (TT) is a medical emergency that requires immediate diagnostic evaluation. Photoacoustic imaging (PAI) has the potential to provide spatially resolved oxygen saturation (sO2), which can serve as a valuable marker in TT diagnosis. We investigated the potential of PAI as an alternative method for TT diagnosis and testicular injury assessment. We measured sO2 levels in different degrees of TT models using PAI at various time points. Based on histopathological results, we found that the averaged sO2 per pixel (sO2̅) and reduction of sO2̅ (rsO2) in twisted testicles had significant correlations with hypoxic conditions. Both sO2̅ and rsO2 exhibited excellent diagnostic abilities in detecting TT and identifying ischemia/hypoxia injury following TT. Furthermore, PAI-measured sO2 demonstrated favorable diagnostic capabilities in discriminating if the testicle had suffered irreversible injury. In summary, PAI presents a potentially promising novel approach in evaluating TT and warrants further clinical investigation.