Visualization of ischemic stroke-related changes on ¹⁸F-THK-5351 positron emission tomography

Background: The ¹⁸F-THK-5351 radiotracer has been used to detect the in vivo tau protein distribution in patients with tauopathy, such as Alzheimer’s disease and corticobasal syndrome. In addition, ¹⁸F-THK-5351 can also monitor neuroinflammatory process due to high affinity to astrogliosis. We aimed to explore ¹⁸F-THK-5351 distribution patterns and characteristics in patients with recent ischemic stroke. Results: Fifteen patients received ¹⁸F-THK-5351 positron emission tomography (PET) and diffusion tensor imaging (DTI) approximately 3 months after ischemic stroke. A region of interest (ROI) was placed in the peri-ischemic area and was mirrored on the contralateral side as the control, and a proportional value was derived from the ratio of the peri-ischemic ROI value over the mirrored ROI value. Increased ¹⁸F-THK-5351 retention was observed in the areas around and remote from the stroke location. The proportional ¹⁸F-THK-5351 values were negatively correlated with the proportional fractional anisotropy values (r = − 0.39, P = 0.04). Conclusion: ¹⁸F-THK-5351 PET imaging provides a potential tool for in vivo visualization of the widespread ischemia-related changes associated with a microstructural disruption in recent ischemic stroke patients.