360 lines
35 KiB
Markdown
360 lines
35 KiB
Markdown
---
|
|
title: "Irregular Lateral Ventricles"
|
|
docid: "f42ce651-9877-480b-90d8-665be656b33f"
|
|
authors:
|
|
- key: "1fa14dfd-71ea-4960-908e-e720313bc63a"
|
|
value: "Santhosh Gaddikeri, MD"
|
|
- key: "30ce27b2-237f-4aff-a88f-65ead356335b"
|
|
value: "Marinos Kontzialis, MD"
|
|
breadcrumbs:
|
|
-
|
|
name: "Brain"
|
|
slug: "brain"
|
|
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
|
|
-
|
|
name: "Differential Diagnosis"
|
|
slug: "differential-diagnosis"
|
|
treeNodeId: "a7fdd139-664e-4bb8-8d18-400e4733ff60"
|
|
-
|
|
name: "Ventricles, Periventricular Regions"
|
|
slug: "ventricles-periventricular-regions"
|
|
treeNodeId: "353c434a-a6fc-4ef1-8786-d30a1988a4dc"
|
|
-
|
|
name: "Generic Imaging Patterns"
|
|
slug: "generic-imaging-patterns"
|
|
treeNodeId: "969c31a2-ef56-4fc3-9125-05857cf9aac3"
|
|
-
|
|
name: "Irregular Lateral Ventricles"
|
|
slug: "irregular-lateral-ventricles"
|
|
treeNodeId: null
|
|
category: "Brain"
|
|
documentVersionId: "2594bf27-49d6-4896-8859-f9eee7b4228c"
|
|
imageCount: 42
|
|
lastUpdated: "02/15/23"
|
|
pageDescription: "Irregular Lateral Ventricles"
|
|
pageKeywords: "Brain, Differential Diagnosis, Ventricles, Periventricular Regions, Generic Imaging Patterns, Irregular Lateral Ventricles"
|
|
pageTitle: "Irregular Lateral Ventricles | STATdx"
|
|
enhancedTitle: "Irregular Lateral Ventricles"
|
|
type: "DDX"
|
|
references: true
|
|
breadcrumbs:
|
|
- "Brain"
|
|
- "Differential Diagnosis"
|
|
- "Ventricles, Periventricular Regions"
|
|
- "Generic Imaging Patterns"
|
|
- "Irregular Lateral Ventricles"
|
|
---
|
|
# ESSENTIAL INFORMATION
|
|
|
|
- ## Key Differential Diagnosis Issues
|
|
|
|
|
|
- Irregular ventricles may be result of obstruction, chronic volume loss, &/or congenital deformities
|
|
- Obstruction: Mass effect, ballooned-appearing ventricles, and transependymal CSF migration
|
|
- Volume loss: Ventricle irregularity with brain parenchymal loss
|
|
- Congenital: Look for associated findings (colpocephaly, subependymal nodules)
|
|
- Ventricular deformities may become permanent despite relief of obstruction due to parenchymal atrophy or acquired ventricular noncompliance
|
|
- Enhancement may help differentiate etiologies
|
|
- ## Helpful Clues for Common Diagnoses
|
|
|
|
|
|
- **CSF Shunts and Complications**
|
|
- Common complications include shunt obstruction/breakage, infection, overdrainage
|
|
- Acquired ventricular noncompliance may result in ventricle deformity
|
|
- Small, "slit" ventricles → noncompliant ventricle syndrome, chronic overdrainage
|
|
- **Surgical Defects**
|
|
- Often evident from prior shunt tract or burr hole
|
|
- Overlying skull or scalp may show defect
|
|
- Deformity is chronic
|
|
- **Periventricular Leukomalacia**
|
|
- Selective vulnerability of periventricular white matter of preterm neonate
|
|
- Injury in late 2nd or early 3rd trimester
|
|
- Thinning of posterior body of corpus callosum, enlargement and irregularity of lateral ventricular walls
|
|
- Colpocephaly: Atrium/occipital horns dilated
|
|
- Related to spastic cerebral palsy
|
|
- **Cerebral Infarction, Chronic**
|
|
- Vascular territory wedge-shaped area of encephalomalacia
|
|
- Results in compensatory or ex vacuo dilation of regional ventricle due to volume loss
|
|
- **Multiple Sclerosis**
|
|
- Multiple periventricular/perivenular and callososeptal T2 hyperintensities
|
|
- Confluent lesions in severe disease lead to atrophy and irregular ventricular margins
|
|
- **Porencephalic Cyst**
|
|
- Congenital porencephalic cysts result from intrauterine vascular or infectious injury
|
|
- Acquired cysts are secondary to injury later in life from trauma, surgery, ischemia, or infection
|
|
- CSF intensity cysts with smooth walls and T2-hyperintense surrounding gliotic changes (no gray matter lining walls as in open-lip schizencephaly)
|
|
- Usually communicate directly with ventricular system
|
|
- ## Helpful Clues for Less Common Diagnoses
|
|
|
|
|
|
- **Chiari 2**
|
|
- Pointed anterior horns, colpocephaly
|
|
- Small, crowded posterior fossa, widening of tentorial incisura, towering cerebellum, tectal beaking, downward herniation of cerebellar vermian tissue through foramen magnum
|
|
- Associated with lumbar myelomeningocele
|
|
- Hydrocephalus and other midline malformations
|
|
- **Heterotopic Gray Matter**
|
|
- Subependymal heterotopia: Subependymal nodules follow gray matter signal and protrude into ventricles; no enhancement
|
|
- Focal/multifocal asymmetric gray matter indentation of ventricle
|
|
- **Tuberous Sclerosis Complex**
|
|
- Subependymal nodules lining ventricles characteristic
|
|
- Mostly along striothalamic groove
|
|
- Calcify with increasing age
|
|
- < 1.3 cm
|
|
- Cortical and subcortical tubers are usually multifocal ± mild mass effect
|
|
- Tubers most easily seen on FLAIR
|
|
- Rarely, tubers may calcify or enhance
|
|
- White matter radial migration lines
|
|
- Cyst-like white matter lesions (cystoid brain degeneration)
|
|
- Enhancing mass with rapid growth at foramen of Monro = subependymal giant cell astrocytoma
|
|
- **Metastases, Intracranial, Other**
|
|
- CSF seeding of primary CNS tumors, lymphoma, or systemic malignancy may cause irregular ventricles
|
|
- Intraventricular metastases = 0.9-4.6% of cerebral metastases
|
|
- Adults: Renal, colon, lung
|
|
- Children: Neuroblastoma, Wilms tumor, retinoblastoma
|
|
- May result in ventricular nodules, which can deform ventricles
|
|
- Lateral ventricles most common location
|
|
- Avid enhancement ± vasogenic edema in adjacent parenchyma
|
|
- **Intraventricular Webs or Adhesions**
|
|
- May be congenital or acquired (prior hemorrhage, infection, or tumor)
|
|
- Contours of ventricles may be rounded or balloon-like due to obstructive symptoms
|
|
- Contrast ventriculography or cine CSF can be helpful to assess for evidence of physiological flow obstruction
|
|
- Heavily weighted T2 sequences, such as FIESTA/CISS, helpful
|
|
- **CMV, Congenital**
|
|
- Microcephaly
|
|
- Periventricular calcifications 40-70%
|
|
- Migrational abnormalities: Lissencephaly, pachygyria, polymicrogyria, schizencephaly
|
|
- Delayed myelination, dysmyelination
|
|
- Cerebral + cerebellar volume loss
|
|
- Periventricular cysts, ventriculomegaly, ventricular adhesions, lenticulostriate vasculopathy
|
|
- **Schizencephaly**
|
|
- Transmantle cleft lined by gray matter
|
|
- Open lip (large defect), closed lip (small defect)
|
|
- Dimple in wall of ventricle when defect small/closed
|
|
- Up to 50% bilateral
|
|
- When bilateral, 60% are open lipped on both sides
|
|
- ## Helpful Clues for Rare Diagnoses
|
|
|
|
|
|
- **Hemimegalencephaly**
|
|
- Hamartomatous overgrowth of part/all of hemisphere
|
|
- Lateral ventricle ipsilateral to enlarged hemisphere is usually bizarre-shaped and typically enlarged
|
|
- Involved hemisphere may eventually atrophy from chronic seizures
|
|
- **Holoprosencephaly**
|
|
- Congenital structural forebrain anomalies defined by degree of frontal lobe fusion
|
|
- All types have absent septum pellucidum and frontal lobe fusion anomaly
|
|
- Alobar
|
|
- Single midline forebrain
|
|
- Single primitive monoventricle, often incompletely covered posteriorly by brain (dorsal cyst)
|
|
- Semilobar
|
|
- Frontal lobes > 50% fused
|
|
- Thalami and hypothalamus may be fused
|
|
- Interhemispheric fissure and falx cerebri may be present posteriorly
|
|
- Facial malformations mild or absent
|
|
- Lobar: Anterior lateral ventricle may be deficient
|
|
- Interhemispheric fissure present along most of midline
|
|
- Only most inferior frontal lobes fused
|
|
- Thalami almost/completely separated
|
|
- Callosal dysgenesis (genu, rostrum)
|
|
- **Holoprosencephaly Variants**
|
|
- Middle interhemispheric variant of holoprosencephaly
|
|
- Lack of separation in posterior frontal and parietal areas
|
|
- Dorsal cyst in 40%
|
|
- Callosal dysgenesis (body)
|
|
- ## Alternative Differential Approaches
|
|
|
|
|
|
- Gadolinium studies can differentiate among causes of ependymal nodules
|
|
- Nonenhancing subependymal nodules may represent gray matter heterotopia or tuberous sclerosis nodules
|
|
- Gray matter heterotopias follow gray matter signal/density
|
|
- Tuberous sclerosis nodules follow white matter signal or are calcified
|
|
- Enhancing nodules suggest ependymal tumor seeding
|
|
|
|
## References
|
|
|
|
# Selected References
|
|
|
|
1. [Balasubramaniam C: Shunt complications - staying out of trouble. Neurol India. 69(Supplement):S495-501, 2021](http://www.ncbi.nlm.nih.gov/pubmed/?term=35103008%5Bpmid%5D)
|
|
1. [Society for Maternal-Fetal Medicine (SMFM) et al: Holoprosencephaly. Am J Obstet Gynecol. 223(6):B13-6, 2020](http://www.ncbi.nlm.nih.gov/pubmed/?term=33168217%5Bpmid%5D)
|
|
1. [Gotardo JW et al: Impact of peri-intraventricular haemorrhage and periventricular leukomalacia in the neurodevelopment of preterms: a systematic review and meta-analysis. PLoS One. 14(10):e0223427, 2019](http://www.ncbi.nlm.nih.gov/pubmed/?term=31600248%5Bpmid%5D)
|
|
1. [Winter TC et al: Holoprosencephaly: a survey of the entity, with embryology and fetal imaging. Radiographics. 35(1):275-90, 2015](http://www.ncbi.nlm.nih.gov/pubmed/?term=25590404%5Bpmid%5D)
|
|
1. [Smith AB et al: From the radiologic pathology archives: intraventricular neoplasms: radiologic-pathologic correlation. Radiographics. 33(1):21-43, 2013](http://www.ncbi.nlm.nih.gov/pubmed/?term=23322825%5Bpmid%5D)
|
|
1. [Osborn AG et al: Intracranial cysts: radiologic-pathologic correlation and imaging approach. Radiology. 239(3):650-64, 2006](http://www.ncbi.nlm.nih.gov/pubmed/?term=16714456%5Bpmid%5D)
|
|
1. [Melhem ER et al: Periventricular leukomalacia: relationship between lateral ventricular volume on brain MR images and severity of cognitive and motor impairment. Radiology. 214(1):199-204, 2000](http://www.ncbi.nlm.nih.gov/pubmed/?term=10644124%5Bpmid%5D)
|
|
|
|
|
|
## Images
|
|
|
|
|
|
### Selected Images
|
|
|
|

|
|
**CSF Shunts and Complications**
|
|
*Axial T2 MR in a patient with chronic shunting demonstrates slit-like irregular lateral ventricles <img src='img/arrows/CS.png'/> due to noncompliance from chronic drainage.*
|
|
|
|

|
|
**Surgical Defects**
|
|
*Axial FLAIR MR demonstrates a large surgical defect in the left frontal lobe <img src='img/arrows/CS.png'/> due to prior tumor resection communicating with the left lateral ventricle <img src='img/arrows/CO.png'/>, which appears irregular.*
|
|
|
|

|
|
**Periventricular Leukomalacia**
|
|
*Axial T2 MR in a 5-year-old boy with spastic cerebral palsy demonstrates irregular lateral ventricles <img src='img/arrows/CO.png'/> with paucity of white matter and periventricular hyperintensities <img src='img/arrows/CS.png'/>, consistent with periventricular leukomalacia.*
|
|
|
|

|
|
**Cerebral Infarction, Chronic**
|
|
*Axial T2 MR demonstrates encephalomalacia in the left occipital lobe <img src='img/arrows/CO.png'/> with ex vacuo dilation of left occipital horn <img src='img/arrows/CS.png'/> due to PCA territory chronic infarct.*
|
|
|
|

|
|
**Multiple Sclerosis**
|
|
*Axial T2 MR in a patient with primary progressive MS demonstrates extensive white matter hyperintensities <img src='img/arrows/CS.png'/> with asymmetric parenchymal volume loss and ex vacuo dilation of lateral ventricles <img src='img/arrows/CO.png'/>.*
|
|
|
|

|
|
**Porencephalic Cyst**
|
|
*Axial T2 MR demonstrates a right occipital lobe, smooth-walled, cystic encephalomalacia <img src='img/arrows/CO.png'/> lined by white matter <img src='img/arrows/CS.png'/> and communicating with the lateral ventricle, consistent with porencephalic cyst.*
|
|
|
|

|
|
**Chiari 2**
|
|
*Axial NECT demonstrates irregular lateral ventricles <img src='img/arrows/CO.png'/> with a right frontal lobe shunt catheter <img src='img/arrows/CS.png'/>. Note diffuse calvarial thickening <img src='img/arrows/CC.png'/> due to chronic shunting. Images of posterior fossa revealed small posterior fossa and other stigmata of Chiari 2 malformation (not shown).*
|
|
|
|

|
|
**Heterotopic Gray Matter**
|
|
*Axial T2 MR demonstrates nodular gray matter heterotopia <img src='img/arrows/CS.png'/> along the ependymal lining of bilateral occipital horns.*
|
|
|
|

|
|
**Tuberous Sclerosis Complex**
|
|
*Axial 3D T1 MPRAGE in a patient with known tuberous sclerosis demonstrates multiple subependymal nodules <img src='img/arrows/CS.png'/>. Also note tiny cysts in white matter <img src='img/arrows/CO.png'/>. Cortical/ subcortical tubers and white matter radial migration lines were seen (not shown).*
|
|
|
|

|
|
**Metastases, Intracranial, Other**
|
|
*Axial T1 C+ MR in a patient with metastatic lung cancer demonstrates multiple heterogeneously enhancing metastatic lesions in bilateral periventricular regions <img src='img/arrows/CS.png'/>.*
|
|
|
|

|
|
**Intraventricular Webs or Adhesions**
|
|
*Axial 3D T2 HASTE MR in a neonate demonstrates multiple septa/webs in both lateral ventricles <img src='img/arrows/CS.png'/>. Also note asymmetrically dilated, irregular lateral ventricles <img src='img/arrows/CC.png'/>. Encephalomalacia in the right parietooccipital region <img src='img/arrows/CO.png'/> is due to antenatal insult.*
|
|
|
|

|
|
**CMV, Congenital**
|
|
*Axial NECT in a 2-year-old with a known congenital CMV infection demonstrates moderately dilated irregular lateral ventricles <img src='img/arrows/CS.png'/> as well as periventricular and deep white matter calcifications <img src='img/arrows/CC.png'/>. Note lissencephalic gyral pattern <img src='img/arrows/CO.png'/>.*
|
|
|
|

|
|
**Schizencephaly**
|
|
*Axial 3D T1 MR demonstrates open-lip schizencephaly with a seam connecting ependymal to pial surface <img src='img/arrows/CS.png'/>. Note gray matter lining the cystic area <img src='img/arrows/CO.png'/>, differentiating it from a porencephalic cyst.*
|
|
|
|

|
|
**Holoprosencephaly Variants**
|
|
*Axial T2 MR demonstrates absent septum <img src='img/arrows/CS.png'/> with absent posterior body of corpus callosum. Also seen was abnormal bilateral sylvian fissure with ventricle orientation and midline fusion (not shown), consistent with syntelencephaly, a.k.a. middle interhemispheric variant holoprosencephaly.*
|
|
|
|
|
|
### Additional Images
|
|
|
|

|
|
**CSF Shunts and Complications**
|
|
*Axial NECT shows a right frontal ventricular drain that traverses the right ventricle but is not decompressing the left lateral ventricle, which remains irregularly enlarged <img src='img/arrows/WC.png'/>.*
|
|
|
|

|
|
**Surgical Defects**
|
|
*Axial T2 MR shows irregular enlargement of the left occipital horn <img src='img/arrows/WS.png'/> due to left temporal and occipital surgical defect and encephalomalacia from tumor removal in this location.*
|
|
|
|

|
|
**Periventricular Leukomalacia**
|
|
*Axial T2 MR shows classic "wavy" or undulating contours of the lateral ventricles <img src='img/arrows/WS.png'/> in addition to colpocephaly (enlargement of the posterior portions of lateral ventricles). Colpocephaly reflects the predominantly posterior volume loss.*
|
|
|
|

|
|
**Cerebral Infarction, Chronic**
|
|
*Axial NECT shows irregular enlargement of the left frontal horn <img src='img/arrows/WO.png'/> due to focal regional parenchymal volume loss in this patient with remote MCA infarct.*
|
|
|
|

|
|
**Heterotopic Gray Matter**
|
|
*Axial T1 FS MR shows multifocal nodularity along ependymal margins of both lateral ventricles <img src='img/arrows/WS.png'/>. These nodules follow gray matter signal on all sequences and do not enhance or change over time.*
|
|
|
|

|
|
**Chiari 2**
|
|
*Axial NECT shows irregularly dilated occipital horns <img src='img/arrows/WS.png'/> with interdigitation of parietal and occipital parenchyma across midline <img src='img/arrows/WC.png'/> due to a falx deficiency.*
|
|
|
|

|
|
**Chiari 2**
|
|
*Coronal T2 MR shows dysgenetic corpus callosum, small posterior fossa, and interdigitation of gyri <img src='img/arrows/WS.png'/> from deficient falx, best seen post shunting. Cerebellum "towers" through the tentorial notch.*
|
|
|
|

|
|
**Tuberous Sclerosis Complex**
|
|
*Axial T2 MR shows multiple calcified subependymal nodules (SEN) <img src='img/arrows/WS.png'/> lining ventricles. Note also subcortical tubers <img src='img/arrows/WC.png'/>. SEN calcify much more commonly than cortical/subcortical tubers. ~ 50% of SEN are calcified by 10 years.*
|
|
|
|

|
|
**Tuberous Sclerosis Complex**
|
|
*Axial T2 MR shows small, subependymal nodules <img src='img/arrows/WS.png'/>, which indent lateral ventricle margins. Unlike gray matter heterotopia, these follow WM signal or are calcified.*
|
|
|
|

|
|
**Metastases, Intracranial, Other**
|
|
*Axial T1 MR shows nodular ependymal thickening with an enhancing rind of tissue along the entire ventricular ependyma <img src='img/arrows/WS.png'/>. While infection & primary malignant brain neoplasms such as GBM, germinoma, and lymphoma commonly spread along ventricular ependyma, this is a recognized but uncommon site for tumor deposits from extracranial primary tumors (melanoma in this case).*
|
|
|
|

|
|
**Schizencephaly**
|
|
*Axial T2 MR shows a small dimple on the lateral ventricular wall, which "points" to the site of a fused pial-ependymal seam <img src='img/arrows/BS.png'/>. The aperture of the cleft is lined by gray matter <img src='img/arrows/WO.png'/> in this closed-lip schizencephaly.*
|
|
|
|

|
|
**Schizencephaly**
|
|
*Axial T2 MR shows cortical dysplasia and open-lip schizencephaly <img src='img/arrows/WS.png'/>. Schizencephaly is closed-lip with a fused, gray matter-lined pial-ependymal seam or open-lip with large, gray matter-lined and fluid-filled CSF clefts.*
|
|
|
|

|
|
**Schizencephaly**
|
|
*Axial NECT shows focal outpouchings of CSF from both lateral ventricles <img src='img/arrows/WS.png'/> with a CSF cleft extending from lateral ventricles to the subpial surface. The pial-ependymal seam is lined by gray matter.*
|
|
|
|

|
|
**Holoprosencephaly**
|
|
*Axial NECT shows septum pellucidum and anterior falx absence. Frontal horns are hypoplastic. A band of parenchyma crosses midline <img src='img/arrows/WS.png'/>. Mild frontal lobe fusion anomalies, as seen here, are typical of lobar holoprosencephaly.*
|
|
|
|

|
|
**Schizencephaly**
|
|
*Axial T1 MR shows open-lip schizencephaly with large, gray matter-lined <img src='img/arrows/CS.png'/> and a fluid-filled CSF cleft. In addition, there is ventricular wall irregularity due to subependymal gray matter heterotopia bilaterally <img src='img/arrows/CO.png'/>.*
|
|
|
|

|
|
**Schizencephaly**
|
|
*Coronal T2 MR demonstrates closed-lip schizencephaly. Abnormal, thick gray matter <img src='img/arrows/CS.png'/> lines the cleft extending to a dimple in the wall of the right lateral ventricle <img src='img/arrows/BS.png'/>.*
|
|
|
|

|
|
**Tuberous Sclerosis Complex**
|
|
*Axial CT shows multiple calcified subependymal nodules <img src='img/arrows/CS.png'/> lining the ventricles in a patient with tuberous sclerosis. The nodules calcify much more commonly than cortical/subcortical tubers. Note traumatic subarachnoid hemorrhage <img src='img/arrows/BS.png'/> in the left Sylvian fissure.*
|
|
|
|

|
|
**Heterotopic Gray Matter**
|
|
*Axial T2 MR shows multiple bilateral subependymal nodules of heterotopic gray matter <img src='img/arrows/CS.png'/> along the lateral ventricular margins. These nodules follow gray matter signal on all sequences.*
|
|
|
|

|
|
**Chiari 2**
|
|
*Axial CT in a Chiari 2 patient shows typical irregular appearance of the ventricles. Note the left posterior shunt catheter <img src='img/arrows/CS.png'/>.*
|
|
|
|

|
|
**Cerebral Infarction, Chronic**
|
|
*Axial FLAIR MR demonstrates left posterior middle cerebral artery encephalomalacia <img src='img/arrows/CS.png'/> with mild ex vacuo dilatation of the left occipital horn and atrium <img src='img/arrows/CO.png'/>.*
|
|
|
|

|
|
**Periventricular Leukomalacia**
|
|
*Axial T2 MR in periventricular leukomalacia shows asymmetric, posterior, periventricular white matter (WM) volume loss with irregular ventricular margins <img src='img/arrows/CS.png'/>. Periventricular leukomalacia, a.k.a. WM injury of prematurity, is a result of brain injury occurring before 33 weeks gestation and resulting in loss of periventricular WM.*
|
|
|
|

|
|
**Surgical Defects**
|
|
*Axial FIESTA MR in a patient following left temporal bone surgery shows skull defect <img src='img/arrows/CS.png'/>, underlying encephalomalacia <img src='img/arrows/CO.png'/>, and ex vacuo dilatation of the left lateral ventricle <img src='img/arrows/BS.png'/>.*
|
|
|
|

|
|
**CSF Shunts and Complications**
|
|
*Axial T1 MR demonstrates a right parietal shunt catheter with its tip <img src='img/arrows/CS.png'/> in the right frontal horn in a patient with congenital aqueductal stenosis. The right lateral ventricle is collapsed, while the 3rd <img src='img/arrows/CO.png'/> and left lateral ventricles <img src='img/arrows/CC.png'/> are moderately dilated.*
|
|
|
|

|
|
**Porencephalic Cyst**
|
|
*Axial CECT shows a low-density outpouching from the right lateral ventricle <img src='img/arrows/CS.png'/>. While a thin rim of cortex seems intact, the cyst nearly reaches brain surface and can be considered a porencephalic dilation or porencephalic lateral ventricle cyst.*
|
|
|
|

|
|
**Metastases, Intracranial, Other**
|
|
*Axial T2 MR shows near-complete coating of the ependymal lining of both lateral ventricles with tumor nodules <img src='img/arrows/CS.png'/> due to metastatic seeding of an anaplastic oligodendroglioma.*
|
|
|
|

|
|
**CMV, Congenital**
|
|
*Axial NECT shows periventricular calcification <img src='img/arrows/CS.png'/>, particularly along the caudostriatal groove, in the context of microcephaly and developmental delay. This strongly suggests congenital CMV infection. Note smooth ventricular margins, unlike calcified nodules in tuberous sclerosis complex.*
|
|
|
|

|
|
**Hemimegalencephaly**
|
|
*Axial T2 MR shows enlargement of left cerebral hemisphere accompanied by an irregular ipsilateral ventricle <img src='img/arrows/CS.png'/>. The body of the left hemispheric WM is bulky. Note left fornix <img src='img/arrows/CC.png'/> overgrowth.*
|
|
|
|

|
|
**Holoprosencephaly**
|
|
*Axial T1 MR shows a large, horseshoe-shaped monoventricle <img src='img/arrows/CC.png'/> with fused basal ganglia <img src='img/arrows/CS.png'/>. There is no interhemispheric fissure and no identifiable lobulation or formation of ventricular horns in this alobar holoprosencephaly.*
|
|
|