Foramen Luschka And Megindie. The foramen of Magendie, also known as the median aperture, is one of the foramina in the ventricular system and links the fourth ventricle and the cisterna magna. It is one of the three sites that cerebrospinal fluid (CSF) can leave the fourth ventricle and enter the subarachnoid space. The two other openings of the fourth ventricle are termed the foramina of Luschka or lateral apertures, one of each on the left and right sides. | Dr. Najeeb