Investigating blood-brain barrier leakage after photothrombotic stroke via DCE-MRI at 9.4T
Summary
Post-stroke epilepsy (PSE) is a phenomenon in which patients experience two or more seizures one week or later upon suffering a stroke. While there is lack of scientific consensus regarding the etiology of PSE, there is evidence that blood-brain-barrier (BBB) disruption is a distinctive component of its origin. However, more insights are required to understand how BBB integrity mediates epileptogenesis. PSE is linked to poor functional recovery, and the sole treatment in use are antiepileptic drugs, which often lead to severe side effects. Thus, fully understanding the BBB integrity’s mediating role in PSE is an important step towards developing alternative treatments. Additionally, novel prognostic tools that can discern stroke patients at risk of developing PSE are needed. Dynamic Contrast Enhanced MRI (DCE-MRI) allows the estimation of BBB permeability by modeling contrast agent (CA) leakage through the BBB in-vivo. Using this method, we aimed to characterize the spatiotemporal evolution of BBB integrity in relation to the development of PSE and identify MRI-based biomarkers that could predict the risk of acquiring PSE. To achieve this, we induced photothrombotic stroke in Sprague-Dawley rats, to mimic stroke in humans. Subsequently, the animals were scanned in a 9.4T MRI scanner, over various timepoints. Scans were conducted between 24 hours and 8 weeks post-procedure, using different concentrations of CA. The concentrations of CA present in the sagittal sinus and lesions were estimated via concentration mapping. Additionally, phantom scans were conducted, to validate in-vivo findings. Together, the data directly contributes to the optimization of DCE-MRI protocols at high field strengths, which can be adopted for a longitudinal study.