An intra parenchymal cyst, follow Csf density on CT or signal intensity on all MRI pulse sequences.
A solitary, uni locular, round to ovoid cyst smooth, thin imperceptible epithelial lined wall.
No calcfication within the cyst or along its wall.
Non enhancing on post contrast.
No restricted diffusion on MRI Diffusion.
Frontal lobe white matter is most common and typical location. Temporal lobe is second common site.
Size vary from few mm to several cm.
Occur in any age group. No gender preponderance.
Common in pts screened for headache and seizures. Clinical significance in a case is doubtful and needs clinical and EEG correlation.
Enlarged peri vascular space : usually occur in cluster, common in basal ganglia, less commonly in parietal lobe white matter, rarely mid brain.
Arachonoid cyst : Extra axial.
Ependymal cyst : Intra ventricular.
Porencephalic cyst: Communicate with subarachnoid Csf spaces along cerebral convexity or ventricles. Being an end result of parenchymal Gliosis usually show a thin hyperintense of rim Gliosis along the adjacent brain parenchyma lining cyst on FLAIR where rest of the cyst show complete signal suppression as that of Csf on FLAIR.