https://radiopaedia.org/articles/velum-interpositum
The velum interpositum is a small membrane containing a potential space just above and anterior to the pineal gland which can become enlarged to form a cavum velum interpositum.
Gross anatomy
The velum interpositum is formed by an invagination of pia mater forming a triangular membrane the apex of which points anteriorly.
The velum interpositum is a small membrane containing a potential space just above and anterior to the pineal gland which can become enlarged to form a cavum velum interpositum.
Gross anatomy
The velum interpositum is formed by an invagination of pia mater forming a triangular membrane the apex of which points anteriorly.
Boundaries
superiorly: the columns of the fornices and hippocampal commissure (psalterium) reaching as far forward as the foramen of Monro
inferiorly: the internal cerebral veins and tela choroidea of the third ventricle
inferolaterally: the thalamus
posteriorly: the narrow base of the triangle abuts the splenium of the corpus callosum 1
It varies in shape from persion to person, sometimes interposed between the internal cerebral veins and splenium, and depending on whether or not there is a cavum vergae (in which case the columns of the fornices are displaced inferiorly, narrowing the velum interpositum).
When somewhat distended by fluid it forms a small triangular (in axial section) space and is referred to as a cavum velum interpositum. If larger and exterting mass effect it is known as a cavum velum interpositum cyst.
superiorly: the columns of the fornices and hippocampal commissure (psalterium) reaching as far forward as the foramen of Monro
inferiorly: the internal cerebral veins and tela choroidea of the third ventricle
inferolaterally: the thalamus
posteriorly: the narrow base of the triangle abuts the splenium of the corpus callosum 1
It varies in shape from persion to person, sometimes interposed between the internal cerebral veins and splenium, and depending on whether or not there is a cavum vergae (in which case the columns of the fornices are displaced inferiorly, narrowing the velum interpositum).
When somewhat distended by fluid it forms a small triangular (in axial section) space and is referred to as a cavum velum interpositum. If larger and exterting mass effect it is known as a cavum velum interpositum cyst.