TSPO and stroke disorder: Moreover, using positron emission tomography (PET) and T1-weightedMRI, Gerhard et al. measured increased [11C]-PK11195 binding, a ligand selective for translocator protein (TSPO) which is particularly abundant on activated microglia within the infarcted hemisphere of stroke patients as early as day 3 and even out to day 53 post-stroke [92,93].