Detecting Changes in Reactive Oxygen Species in the Brain by GSH-Thiol-Weighted Imaging via Variable Delay Multipulse Chemical-Exchange Saturation Transfer.

: Detecting changes in reactive oxygen species (ROS) is critical for understanding its role in brain health and diseases. We assumed that GSH-thiol-weighted imaging could potentially reflect subtle changes in the ROS in the microenvironment. In this study, we aimed to investigate the capability of GSH-thiol-weighted imaging via VDMP-CEST in detecting alterations of ROS within the brain. : To develop a new technique to image GSH-thiol, phantoms of different GSH concentrations under acidic and weakly alkaline conditions were performed using MRI CEST scanning. To explore the ability of GSH-thiol-weighted VDMP-CEST imaging to detect changes in ROS, experiments were conducted in vitro and in vivo. Phantom imaging in different concentrations of GSH and HO was performed. Eight normal rats underwent rat brain imaging, followed by in vitro ROS detection. Another four rats underwent rat brain imaging before and after sleep deprivation. : We found that VDMP-CEST could achieve GSH-thiol-weighted imaging under both acid and weakly alkaline conditions. This signal decreased with the mixing time. We also demonstrated that GSH-thiol-weighted VDMP-CEST imaging can reflect alterations in ROS in vitro and in vivo. In vitro, the GSH-thiol-weighted VDMP-CEST signal was sensitive to changes in HO concentration. In vivo, the GSH-thiol-weighted VDMP-CEST signal has regional heterogeneity, which is positively correlated with ROS content in vitro ( = 0.7404, < 0.0001). Furthermore, this signal significantly increased after sleep deprivation (whole brain: < 0.05, hippocampus: < 0.01). : This study demonstrates that GSH-thiol-weighted imaging via VDMP-CEST can serve as a new method for detecting changes in ROS in the brain.