T2 weighted magnetic resonance imaging (MRI) of the head in coronal view. This is a T2 weighted magnetic resonance imaging (MRI) of the head in coronal view that is showing the full longitudinal extent of the cyst of the cavum septum pellucidum et vergae. Lateral bowing of the walls of the cavum is clearly visible which is one of the criteria required to diagnose a cyst of the cavum septum pellucidum.