Quantitative Susceptibility Mapping and R2* of Ischemia-reperfusion Injury and its Relationship with Reactive Oxygen Species Activity

Motivation: There is a need for specific imaging of ischemia-reperfusion injury (IRI) as it initiates infarct iron deposition, catalyzing reactive oxygen species (ROS) production and heart failure. Goal(s): Our goal was to assess and image the relationships between susceptibility, R2*, and ROS activity. Approach: Six swine with IRI were imaged to quantify iron using QSM and R2*, and to measure ROS activity. Results: Regions of hemorrhage and infarct had higher susceptibility, R2* and ROS activity compared to remote regions. There was a positive correlation between infarct ROS activity and R2* in the hemorrhage, and between infarct ROS activity and susceptibility in the hemorrhage. Impact: The observed associations between magnetic susceptibility and R2* with ROS activity allows for better understanding of IRI and potential to develop new targeted interventions. This suggests that iron could be a catalyst for ROS production in ischemia-reperfusion injury.