Classification of MRI findings according to severity
| Malformation Type | Severity | ||
|---|---|---|---|
| Normal Variant | Minor Findings | Major Findings | |
| NTD | Meningocele | Acrania/anencephaly encephalocele | |
| Myelocele | |||
| Cystic lesions | CPC | Isolated PVPC | Nonisolated PVPC |
| Cavum verge | Arachnoid cyst | PVL | |
| CVI | Porencephalic cyst | ||
| Bleeding | IVH grade 1 | IVH grade 2–4 | |
| Ischemia | Parenchymatic damage | ||
| Cortical disorders | Delayed sulcation (up to 2 weeks) | Lissencephaly | |
| Schizencephaly | |||
| Heterotopia | |||
| Microcephaly | |||
| White matter | Isolated T2 hypersignal | Nonisolated T2 hypersignal | |
| Midline CC | Lipoma | Short intact CC thick/thin | Complete/partial CC agenesis |
| Midline CSP | Isolated septal agenesis | SOD | |
| Posterior fossa | MCM | Blake pouch cyst | Chiari 2 |
| DWS | |||
| Primary disruption of cerebellum/vermis/brain stem | |||
| Secondary disruption of cerebellum/vermis/brain stem | |||
| Vascular | Vein of Galen aneurysm | ||
Note:—NTD indicates neural tube defect; CPC, choroid plexus cyst; CVI, cavum vellum interpositum; PVPC, periventricular pseudocyst; PVL, periventricular leukomalacia; IVH, intraventricular hemorrhage; CMV, cytomegalovirus; CC, corpus callosum; CSP, cavum septum pellucidum; SOD, septo-optic dysplasia; MCM, mega cysterna magna; DWS, Dandy-Walker syndrome; CSVT, cerebral sinovenous thrombosis.