Ambient Cistern

Ambient Cistern

Ashley Davidoff MD

The Common Vein Copyright 2010 

Definition

The ambient cistern is an expansion of the subarachnoid space around the midbrain between the interpeduncular cistern anteriorly and the quadrigeminal plate cistern posteriorly.  Laterally it extends behind the posterior aspect of the thalamus.  The posterior cerebral artery and the basal vein lie anteriorly in the cistern.

Suprasellar Cistern and other Cisterns Surrounding the Midbrain

The axial CTscan through the midbrain shows the suprasellar cistern with a stellate shape anteriorly and enclosing vessels of the circle of Willis. Posteriorly the suprasellar cistern fuses with the interpeduncular cistern anteriorly, the ambient cisterns laterally, and quadrigeminal plate cisterns posteriorly.

Image Courtesy Ashley Davidoff MD Copyright 2010 All rights reserved 94013b.9s

 Ambient Cistern

23125 head brain clot cisterna magna MRI T2 Courtesy James Donnelly MD Uploaded RP

Ambient Cistern and Suprasellar Cistern

The next axial level down is still through the midbrain but it is now surrounded by the ambient cisterns and the stellate shaped suprasellar cistern

Courtesy Ashley Davidoff copyright 2010 94013b.82s

 http://www.med.harvard.edu/aanlib/cases/casem/mr1_t/021.html Mickey Mouse

Basal Cisterns in Sagittal Section

The overlay outlines the basal cisterns in light blue, and the ventricles (teal blue), and a variety of cerebral structures including the midbrain (mb) pons, medulla (med) and cerebellum. A variety of blood vessels (overlaid in blue and red are related to the basal cisterns. The image is T2 weighted sagittal MRI sequence from a patient with a macroadenoma of the pituitary (green p). Starting inferior and anterior we follow the pontine or prepontine cistern associated with the basilar artery, the interpeduncular cistern which is an anterior to the peduncles of the midbrain, the suprasellar cistern (above the pituitary – green p), and the cavum interpositum. Posteriorly the quadrigeminal plate cistern lies behind the colliculi and finally the cisterna magna which surrounds the inferior aspect of the medulla and cerebellum and merges with the subarachnoid space around the cord. The peripheral dural sinuses include the superior sagittal sinus, the laterally placed junction of the transverse sinus and straight sinus, and the confluens of the inferior sagittal sinus which runs on the inferior surface of the falx and the straight sinus which lies on the posterior and superior surface of the tentorium overlying the cerebellum.

Image Courtesy Ashley Davidoff MD Copyright 2010 All rights reserved 98287b03L02b.9s

Vessels Associated with the Cisterns

The overlay outlines the basal cisterns in light blue, and the ventricles (teal blue), and a variety of cerebral structures including the midbrain (mb) pons, medulla (med) and cerebellum. A variety of blood vessels (overlaid in blue and red are related to the basal cisterns. The image is T2 weighted sagittal MRI sequence from a patient with a macroadenoma of the pituitary (green p). Starting inferior and anterior we follow the pontine or prepontine cistern associated with the basilar artery, the interpeduncular cistern which is anterior to the peduncles of the midbrain. The suprasellar cistern (above the pituitary – green “p”) is associated with the posterior aspect of the circle of Willis The cavum velum interpositum is associated with the optic tract (yellow) and the anterior vessels of the circle of Willis. Posteriorly the quadrigeminal plate cistern lies behind the colliculi lies anterior to the tentorium where the internal cerebral vein and vein of Rosenthal enter the vein of Galen (blue vein) to enter the straight sinus. Finally the cisterna magna which surrounds the inferior aspect of the medulla and cerebellum merges with the subarachnoid space around the cord where the vertebral artery and posterior inferior cerebellar artery run.

Image Courtesy Ashley Davidoff MD Copyright 2010 All rights reserved 98287b03L03.9s

References

Ryan S McNicholas M, and Eustace S.  Anatomy for Diagnostic Imaging Second Edition Elsevier Health Sciences