Development of a noninvasive redox imaging method that can stably detect radiation-induced intestinal injury.

The intestine is an important organ in radiotherapy of the abdominal region, and radiation-induced intestinal injury (RIII) is an undesirable biological response to radiotherapy. Radiotherapy is known to induce oxidative stress associated with the generation of reactive oxygen species (ROS), which in turn plays an important role in RIII. However, these effects cannot be detected or predicted early using conventional imaging techniques such as computed tomography and magnetic resonance imaging (MRI). In this study, an intestinal redox imaging method using dynamic nuclear polarization (DNP) MRI and carbamoyl PROXYL (CmP) was designed. The probe was prepared in a solution of increased viscosity of the CmP solution that is not affected by peristalsis. This redox imaging method enabled noninvasive redox imaging of the intestine and detection of RIII at an early stage of progression. Our findings suggest that redox imaging can aid in monitoring early metabolic changes that occur during the pathogenesis of this condition.