This document summarizes various types of nonneoplastic and noninflammatory intracranial cysts. It describes the imaging appearance and characteristics of colloid cysts, Rathke's cleft cysts, neuroepithelial cysts, neuroenteric cysts, pineal cysts, choroid plexus cysts, CSF-like choroidal fissure and parenchymal cysts, enlarged Virchow-Robin spaces, and interhemispheric cysts. For each type of cyst, the document provides examples of MRI or CT images and discusses the differential diagnosis.

1. Nonneoplastic & noninflammatory
intracranial cysts
Dr Ahmed Esawy

2. andNonneoplastic
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 ventricleDr Ahmed Esawy

3. Colloid cystColloid cyst
Dr Ahmed Esawy

4. • MRI appearance
• : variable signals depending on the contents
T1 hyperintense or hypo intense
T2 hyperintense or hypo intense
Colloid cystColloid cyst
Dr Ahmed Esawy

5. colloid cysts
Dr Ahmed Esawy

6. 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

7. 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

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

9. 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

10. 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

11. 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

12. Differential Diagnosis
• Craniopharyngioma
• cystic pituitary adenoma
• nonneoplastic cysts Unlike Rathke cleft cysts
Dr Ahmed Esawy

13. • 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

14. 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

15. Choroids Plexus Cyst
Dr Ahmed Esawy

16. Choroids Plexus Cyst
Dr Ahmed Esawy

17. Multiple small choroid plexus cysts in a normal infant..
Dr Ahmed Esawy

18. 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

19. 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

20. 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

21. Differential Diagnosis
• multiple lacunar infarcts
• cystic neoplasms
• infectious cysts (Neurocysticercosis cysts )
.
Dr Ahmed Esawy

22. 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

23. Differential Diagnosis
• CPC
• arachnoid cyst
• neurocysticercosis
• asymmetric ventricles
Dr Ahmed Esawy

24. 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

25. 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

26. Differential Diagnosis
• enlarged PVS
• infectious cyst
• porencephalic cyst
• arachnoid cyst
Dr Ahmed Esawy

27. 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

28. 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

29. 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

30. Differential Diagnosis
• epidermoid cyst
• arachnoid cyst
• endodermal cysts (Rathke and colloid)
Dr Ahmed Esawy

31. 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

32. 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

33. 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

34. Type II dilated VR spaces in a 6-year-old boy
FALIRT2
punctate hyperintense areas around the
occipital horns
Dr Ahmed Esawy

35. 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

36. 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

37. 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

38. MR Imaging of CSF-Iike Choroidal
Fissure and Parenchymal Cysts of the Brain
Dr Ahmed Esawy

39. T1
T2
Left choroidal fissure
cyst (arrows) in 36-
year-old man
Dr Ahmed Esawy

40. T1
Right choroidal fissure cyst 31 y
right temporal lobe lesion (arrowheads)
Dr Ahmed Esawy

41. T2
T1
T1
Right choroidal fissure
cyst 31 y
right temporal lobe
lesion (arrowheads)
Dr Ahmed Esawy

42. • Left choroidal fissure cyst (arrows)
• 13-year-old girl
• cyst between mesial temporal lobe and brainstem is seen on
T1
T2
Dr Ahmed Esawy

43. • 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

44. T2
Right choroidal fissure cyst
(arrowheads) in 27-year-old man
Dr Ahmed Esawy

45. 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

46. 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

47. T2
T1
T1
Right thalamic multiseptated cyst
(arrows)
in 66-year-old woman
isointensity of cyst with CSF.
Dr Ahmed Esawy

48. Interhemispheric cysts associated with
callosal agenesis
Dr Ahmed Esawy

49. Dr Ahmed Esawy

50. 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