Velum medullare inferius Last edited and medically reviewed by Alaric Steinmetz on 18.03.2024 Synonyms inferior medullary velum, unteres Kleinhirnsegel, unteres Marksegel The velum medullare inferius, together with the Velum medullare superius, forms the tent-shaped roof of the of the fourth ventricleImaging Enlarge Visualization of the inferior medullary velum (red arrow) on a sagittal T1 sequence from a 7 Tesla MRI.