lateral apertures (of Luschka)
The lateral apertures (of Luschka) (also known as the foramina of Luschka) are two of the foramina in the ventricular system and link the fourth ventricle to the cerebellopontine cistern. Together with the median aperture (of Magendie) they comprise two of the three sites that CSF can leave the fourth ventricle and enter the subarachnoid space.
They are located at the lateral-most aspect of the fourth ventricle and drain into the subarachnoid space at the cerebellopontine angle cistern immediately posterior to the root of the glossopharyngeal (IX) nerve.
When the protruding choroid plexus is calcified, it is known as the Bochdalek flower basket.