5T-ASL: Ruijin's Contrast-Free Technique Maps Brain Blood Flow Precisely

The ultra-high-field multi-delay arterial spin labeling cerebral perfusion imaging technique (5T-ASL), jointly developed by the Department of Radiology at Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine and the Institute of Advanced Medical Imaging Technology, relies on a domestically made 5T ultra-high-field MRI platform to draw a clear map of brain blood flow without injecting contrast agents, providing a reliable basis for surgical decision-making in chronic cerebral infarction. Ms. Chen, 47, suddenly developed slurred speech and weakness in her left limbs in June 2025 and missed the time window for thrombolysis and thrombectomy; imaging confirmed complete occlusion of the M1 segment of the right middle cerebral artery.

The 5T-ASL examination showed that collateral vessels were still providing compensatory blood supply around the infarct core and that some brain tissue retained recovery potential. The diagnosis and treatment team accordingly formulated an individualized minimally invasive interventional plan, the occluded vessel was successfully recanalized after the procedure, and Ms. Chen eventually returned to work and normal life.

The technique has turned cerebrovascular surgery from opening a blind box into precise prediction, significantly improving patient outcomes.