Nonneoplastic & noninflammatory

intracranial cysts

Dr Ahmed Esawy

and Nonneoplastic

cystsinflammatory -non • 37-colloid cysts

• 38-Rathke’s cleft cysts,

• 39-neuroepithelial cysts

• 40-neuroenteric cysts

• 41-pineal cysts.

• 42-Choriod plexus cyst

• 43-CSF-Iike Choroidal Fissure and Parenchymal Cysts of the Brain

• 44-Trigonal cyst

• 45-Interhemispheric cyst

• 46-Dorsal cyst

• 47-Ependymal cysts

• 48-Enlarged VRS

• 49-Cystic trapped 4th ventricle

• 50-Diverticulation of 3rd , lateral ventricle Dr Ahmed Esawy

Colloid cyst Colloid cyst

Dr Ahmed Esawy

• MRI appearance

• : variable signals depending on the contents

T1 hyperintense or hypo intense

T2 hyperintense or hypo intense

Colloid cyst Colloid cyst

Dr Ahmed Esawy

colloid cysts

Dr Ahmed Esawy

Colloid cyst

Characteristic site anterior 3rd ventricle

Characteristic contents

dense viscid mucoid material

(old blood, cholesterol crystals, CSF,various ions)

•CT: hyper dense midline lesion no enhancement

Dr Ahmed Esawy

Colloid cyst

Unenhanced CT. There is a dense, rounded mass in the region of the foramen of Monro causing

enlargement of the lateral ventricles, and indenting the anterior aspect of the third ventricle. Dr Ahmed Esawy

COLLOID CYSTS

• Transverse nonenhanced CT scan shows classic hyperattenuated colloid cyst at foramen of Monro (arrow ( Dr Ahmed Esawy

Differential Diagnosis

• CSF flow artifact (MR pseudocyst (

• neurocysticus cyst may occur at the foramen of Monro.

• Neoplasms such as subependymoma or choroid plexus papilloma

Dr Ahmed Esawy

Rathke cleft cyst T2

smoothly marginated cystic mass (arrows) within and projecting above the pituitary gland. The cyst appears slightly hyperintense relative to gray matter on both T1-weighting (B) and T2-weighting (A). There is no contrast enhancement of its contents or margins

T1 -c

Dr Ahmed Esawy

RATHKE CLEFT CYSTS

• Sagittal postcontrast

• cyst has moderately high protein content and is isointense with brain, not CSF. Location is typical for a Rathke cleft cyst , Dr Ahmed Esawy

Differential Diagnosis

• Craniopharyngioma

• cystic pituitary adenoma

• nonneoplastic cysts Unlike Rathke cleft cysts

Dr Ahmed Esawy

• Enhanced CT scan demonstrates an extra-axial cystic lesion over the left frontal

convexity with two small nodules of rim calcification. There is no contrast

enhancement of the cyst.

Intracranial laterally based

supratentorial neurenteric cyst

Dr Ahmed Esawy

Choroids Plexus Cysts

• Choroid plexus cysts are usually a few

millimeters in diameter and are commonly

located within the body of the plexus. Choroid

plexus cysts may be limited within the body itself

or may protrude into the ventricular cavity .

Isolated choroid plexus cysts occur in about 1%

of all pregnancies.

Dr Ahmed Esawy

Choroids Plexus Cyst

Dr Ahmed Esawy

Choroids Plexus Cyst

Dr Ahmed Esawy

Multiple small choroid plexus cysts in a normal infant..

Dr Ahmed Esawy

CHOROID

PLEXUS CYSTS

Transverse contrast-enhanced T1-weighted bilateral CPCs with peripheral and nodular enhancement (arrows) .

Most CPCs are actually degenerative

xanthogranulomas.

Dr Ahmed Esawy

Differential Diagnosis

• ependymal cyst do not enhance

• villous hyperplasia of the choroid plexus enhances strongly and relatively uniformly.

• Disturbed CSF flow and pseudolesions

• Colloid cysts should not be mistaken for CPCs

Dr Ahmed Esawy

T2 multiple bizarre-appearing cysts (arrows) in centrum semiovale and subcortical white matter of both hemispheres. The cysts vary in size and focally expand but otherwise spare the overlying cortex .

T1+C nonenhancing enlarged PVSs in

right basal ganglia

Enlarged PVSs, Virchow-Robin spaces

isointense to CSF at all pulse sequences

Dr Ahmed Esawy

Differential Diagnosis

• multiple lacunar infarcts

• cystic neoplasms

• infectious cysts (Neurocysticercosis cysts )

.

Dr Ahmed Esawy

EPENDYMAL CYSTS

• FLAIR MR

• enlarged atrium of the left lateral ventricle (open arrow). Signal intensity was isointense to

CSF at all pulse sequences. Note lateral displacement of choroid plexus (solid arrow) Dr Ahmed Esawy

Differential Diagnosis

• CPC

• arachnoid cyst

• neurocysticercosis

• asymmetric ventricles

Dr Ahmed Esawy

Neuroepithelial (ependymal) cyst

Intraventricular cysts 5-year-old male

T2- T2-

cyst within the

right lateral

ventricle with

signal intensity

isointense to

CSF in all

pulse

sequences

T2-

Dr Ahmed Esawy

NEUROGLIAL CYSTS

• neuroglial cyst (straight arrow) adjacent to left temporal horn .

• isointense to CSF at all sequences .

• neuroglial cyst in the choroid fissure (arrow .

AXIAL FLAIR MR

Dr Ahmed Esawy

Differential Diagnosis

• enlarged PVS

• infectious cyst

• porencephalic cyst

• arachnoid cyst

Dr Ahmed Esawy

PINEAL

CYSTS

postmortem slice

Sagittal contrast-enhanced T1

classic benign pineal cyst (straight arrows)

with rim enhancement and mild mass effect

(note slight compression, displacement of

tectal plate [curved arrow) .(]

Dr Ahmed Esawy

Differential Diagnosis

• benign pineal parenchymal neoplasm called a pineocytoma .

• Other cysts in the quadrigeminal cistern that mimic pineal cysts include arachnoid cysts (no calcium) and, rarely,epidermoid cysts

Dr Ahmed Esawy

NEURENTERIC CYSTS

• Sagittal T1

small well-delineated ovoid mass in front of pontomedullary junction (arrow). Mass is hyperintense

compared to CSF. Location and configuration are typical for a neurenteric cyst Dr Ahmed Esawy

Differential Diagnosis

• epidermoid cyst

• arachnoid cyst

• endodermal cysts (Rathke and colloid)

Dr Ahmed Esawy

The Virchow–Robin spaces (VRS) • perivascular compartments surrounding small blood

vessels as they penetrate the brain parenchyma

• Three types

IMAGING CHARACTER

• Characteristic site

• The content of the cysts is CSF-like.

• The adjacent brain parenchyma has normal signal intensity.

• No solid components are identified.

• no enhancement

• Enlarged cause pressure changes Dr Ahmed Esawy

Virchow-Robin Spaces TYPE 1

Proton density FALIR DWI ADC

Bilateral type I VR spaces in a 6-year-old boy

anterior perforated substance on both sides

The signal intensity of the surrounding brain parenchyma is normal

Dr Ahmed Esawy

Virchow-Robin Spaces TYPE 11

Proton density FALIR

Type II VR spaces in a 73-year-old woman hyperintense foci in the

centrum semiovale in both hemispheres

The signal intensity of the surrounding brain parenchyma is normal

FLAIR show old lacunar infarctions(arrow)

Dr Ahmed Esawy

Type II dilated VR spaces in a 6-year-old boy

FALIR T2

punctate hyperintense areas around the

occipital horns

Dr Ahmed Esawy

Type III VR spaces in a 68-year-old man

Proton density FALIR

T2

multiple punctate hyperintense areas in the brainstem ON T2 hypointenese on FLAIR

Dr Ahmed Esawy

Giant VR spaces in the mesencephalothalamic

region in a 19-year-old man.

T2

T1+C

multicystic lesion in the mesencephalothalamic region

Dr Ahmed Esawy

DIFFERENTIAL DIAGNOSIS

of VRS • Lacunar infarction

• Cystic periventricular leukomalacia

• Ovoid MS lesion of the centrum semiovale

• Parenchymal neurocysticercosis in the vesicular stage

• Hurler syndrome (mucopolysaccharidosis type I)

• Desmoplastic pilocytic astrocytoma

• Arachnoid cyst in the perisellar cistern area

• Neuroepithelial cyst of the thalamus

• Choroidal fissure cyst

Dr Ahmed Esawy

MR Imaging of CSF-Iike Choroidal

Fissure and Parenchymal Cysts of the Brain

Dr Ahmed Esawy

T1

T2

Left choroidal fissure

cyst (arrows) in 36-

year-old man

Dr Ahmed Esawy

T1

Right choroidal fissure cyst 31 y

right temporal lobe lesion (arrowheads)

Dr Ahmed Esawy

T2

T1

T1

Right choroidal fissure

cyst 31 y

right temporal lobe

lesion (arrowheads)

Dr Ahmed Esawy

• Left choroidal fissure cyst (arrows) • 13-year-old girl

• cyst between mesial temporal lobe and brainstem is seen on

T1 T2

Dr Ahmed Esawy

• Right choroidal fissure cyst in 74-year-old woman with cerebral atrophy

• Large cyst (arrows) medial to temporal tip of lateral ventricle (arrowheads) , no enhancement of lesion.

T1+C

T1

Dr Ahmed Esawy

T2

Right choroidal fissure cyst

(arrowheads) in 27-year-old man

Dr Ahmed Esawy

Left juxtasylvian cyst in 49-year-old woman loop of middle cerebral artery (small curved arrow) indenting cyst (large arrow). No enhancment

T2 T1+C

Dr Ahmed Esawy

T2

T1

T1

Right juxtasylvian cyst (arrows) in 54-year-old man

Note similarity in shape and location to Branch of middle cerebral artery indents

Dr Ahmed Esawy

T2

T1

T1

Right thalamic multiseptated cyst (arrows) in 66-year-old woman isointensity of cyst with CSF.

Dr Ahmed Esawy

Interhemispheric cysts associated with callosal agenesis

Dr Ahmed Esawy

Dr Ahmed Esawy

The most important condition that must be

distinguished from interhemispheric cysts is

the alobar form of holoprosencephaly

because to treat them as early as possible

in order to prevent gross developmental

deficits

Dr Ahmed Esawy