MAPT and Classical progressive supranuclear palsy: This exploratory study aimed to investigate differences in QSM data of patients with PSP and healthy controls (HCs) and for the first time assess possible correlations between QSM and tau-PET data in patients with PSP to explore the relationship between tau aggregation and iron susceptibility.<h4>Material and methods</h4>We retrospectively investigated differences in susceptibility values of brain structures, as assessed by QSM, between 11 HCs and 31 patients with PSP [Richardson's syndrome (PSP-RS): n = 14; other subtypes (PSP-nonRS): n = 17].