DR/ Hytham Nafady

Cistern Widening of subarachnoid space created by separation of pia and arachnoid. Dura Pia Arachnoid adherent to the skull adherent to the brain surface covers only superficial surface of the brain

Cistern Widening of subarachnoid space created by separation of pia and arachnoid. Subarachnoid hemorrhage

P M IP CH SC CM VI Q PC LT

P M IP CH SC CM VI Q PC LT

P M CH CM VI PC LT

Perimesencephalic cistern 1. Interpeduncular C. 2. Crural C. 3. Ambient C. 4. Quadrigeminal C.

Perimesencephalic cistern 1. Interpeduncular C. 2. Crural C. 3. Ambient C. 4. Quadrigeminal C.

Perimesencephalic cistern 1. Interpeduncular C. 2. Crural C. 3. Ambient C. 4. Quadrigeminal C.

Perimesencephalic cistern 1. Interpeduncular C. 2. Crural C. 3. Ambient C. 4. Quadrigeminal C.

Perimesencephalic cistern 1. Interpeduncular C. 2. Crural C. 3. Ambient C. 4. Quadrigeminal C.

CSF cisterns Median un-paired cisterns Para-median paired cisterns 1-Premedullary 12-Inferior CP angle 2-Prepontine 13-Superior CP angle 3-Interpeduncular 14-Crural 4-Chiasmatic 15-ambient 5-Lamina terminalis 16-Carotid 6-Pericallosal 17-sylvian 7-Quadrigeminal 8-Vellum interpositum 9-Superior cerebellar 10-Cisterna magna 11-Vallecula

Medullary cistern premedullary cistern

Medullary cistern

PICA Cn12 VA

Pontine cistern pre-pontine cistern

Pontine cistern

Pontine cistern Basilar A Ant. Pontomesencephalic V Petrosal V Superior petrosal sinus

Pontine cistern

Pontine cistern AICA BA Cn6 Cn6 BA

Pre-pontine arachnoid cyst

Interpeduncular cistern basal cistern

Interpeduncular cistern

Interpeduncular cistern Cn 3 Interpeduncular cistern

Interpeduncular cistern

Basal v. Interpeduncular V DMCV Ponto- mesencephalic V Basilar A. Interpeduncular V DMCV

Chiasmatic cistern Suprasellar cistern

Chiasmatic cistern Suprasellar cistern

Suprasellar arachnoid cyst

Liliequist membrane The Liliequist membrane is the arachnoid membrane separating the chiasmatic and interpeduncular cisterns.

Liliequist membrane

CH P IP

Third ventriculostomy

Third ventriculostomy

PNSAH Peri-mesencephalic Non-aneurysmal Sub-Arachnoid Hemorrhage. Pre-truncal Non-aneurysmal Sub-Arachnoid Hemorrhage. Brain stem = truncus cerebri. Low pressure bleeding. Source: perimesencephalic vein.

Lamina terminalis cistern

Pericallosal cistern

Pericallosal artery aneurysm

Subarachnoid hemorrhage

Quadrigeminal cistern vein of Galen cistern

Vein of Galen aneurysm

Precentral V Precentral VPrecentral V

Precentral V

Quadrigeminal cistern epidermoid cyst

Superior cerebellar cistern

Vellum interpositum cistern (double layered tela choroidae)

Embryologic Basis for the Development and Anatomy of the Cavum Veli Interpositi

Vellum interpositum cistern

Cavum vili interpositi

Cavum villi interpositi Cavum septum pellucidum & cavum vergae

Cisterna magna Cerebellomedullary cistern

Mega cisterna magna Mega cisterna magna

Vallecula cerebelli Vallecula

Dandy walker variant

CP angle cisterns

CP angle cistern AICA

Superior CP angle cistern AICA AICA AICA AICA

Inferior CP angle cistern Cn 9/10 Cn 10 Cn 9

Inferior CP angle arachnoid cyst

Crural cisterns Between the Crus cerebri (cerebral peduncles Uncus of temporal lobe Medially Laterally

AchA AchAAchA SCA PCA PCA

Carotid cisterns

Sylvian cisterns

Ambient cisterns

Trochlear N.

PCA

Basal vein of Rosenthal

Basal vein of Rosenthal

Basal vein of Rosenthal

Cn 4 epidermoid

Trochlear N. schwannoma

Retro-thalamic cisterns wings of ambient cisterns

Vellum interpositum Retro-thalamic CisternRetro-thalamic Cistern Sup.cerebellar Cistern

Overview of CSF spaces

Overview of CSF spaces Normal: All CSF spaces are visible neither effaced or dilated.

Overview of CSF spaces Normal: All CSF spaces are visible neither effaced or dilated. Atrophy: All CSF spaces are dilated. Hydrocephalus: Ventricles dilated. Subarachnoid spaces effaced. Edema: All CSF spaces are effaced.

Overview of CSF spaces Normal: All CSF spaces are visible neither effaced or dilated. Atrophy: All CSF spaces are dilated.

Overview of CSF spaces Normal: All CSF spaces are visible neither effaced or dilated. Atrophy: All CSF spaces are dilated. Hydrocephalus: Ventricles dilated. Subarachnoid spaces effaced.

Overview of CSF spaces Normal: All CSF spaces are visible neither effaced or dilated. Atrophy: All CSF spaces are dilated. Hydrocephalus: Ventricles dilated. Subarachnoid spaces effaced. Edema: All CSF spaces are effaced.

Benign external hydrocephalus

3 years10 months Benign external hydrocephalus

Benign external hydrocephalus benign enlargement of subarachnoid spaces in infancy Etiology: Immature arachnoid granulations. C.P: Macrocephaly. Normal developmental milestones.

1. Widening of the bifrontal subarachnoid space and anterior interhemispheric fissure (>5mm). 2. Usually normal subaracnoid space posteriorly. 3. No flattening of adjacent gyri. 4. The anterior fontanelle is frequently enlarged. 5. The ventricular system is within normal limits or slightly dilated. 6. There are no pressure effects on the surrounding brain tissue or cerebral atrophy. 7. No blood products on MRI study. 8. another key distinction between benign enlargement of the subarachnoid spaces and a subdural fluid collection is that in the former the cortical veins will be adjacent to the inner table of the calvarium on MR and ultrasound; whereas in the latter the veins are displaced away from the inner table, as the arachnoid membrane and subarachnoid space are displaced.

Benign external hydrocephalus

Benign external hydrocephalus

External hydrocephalus vs subdural hematoma

Hydrocephalus versus atrophy Features that favor hydrocephalus Dilatation of the temporal horns Peri-ventricular interstitial oedema . intra-ventricular flow void from CSF movement on MR Widening of the third ventricular recesses : mid sagittal plane Upward bowing of the corpus callosum : mid sagittal plane Decreased mammillo-pontine distance : mid sagittal plane

Mid-sagittal findings of hydrocephalus Widening of the third ventricular recesses. Upward bowing of the corpus callosum. Decreased mammillo- pontine distance .

Periventricular leukomalacia