The Cavum Septi Pellucidi (CSP), Cavum Vergae (CV) and Cavum Veli Interpositi, are anatomical variants located in the midline of the brain. It is important to identify these conditions to distinguish them from other entities that may require treatment. In this paper, our purpose is to describe MR and CT findings of CSP, CV and Cavum Veli Interpositi, explaining the differential diagnosis.