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title: "Asymmetric Lateral Ventricles"
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docid: "87387f0d-9b20-4288-a250-aa3ec83520c4"
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authors:
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- key: "1fa14dfd-71ea-4960-908e-e720313bc63a"
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value: "Santhosh Gaddikeri, MD"
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- key: "30ce27b2-237f-4aff-a88f-65ead356335b"
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value: "Marinos Kontzialis, MD"
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breadcrumbs:
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-
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name: "Brain"
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slug: "brain"
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treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
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-
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name: "Differential Diagnosis"
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slug: "differential-diagnosis"
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treeNodeId: "a7fdd139-664e-4bb8-8d18-400e4733ff60"
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-
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name: "Ventricles, Periventricular Regions"
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slug: "ventricles-periventricular-regions"
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treeNodeId: "353c434a-a6fc-4ef1-8786-d30a1988a4dc"
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-
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name: "Generic Imaging Patterns"
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slug: "generic-imaging-patterns"
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treeNodeId: "969c31a2-ef56-4fc3-9125-05857cf9aac3"
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-
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name: "Asymmetric Lateral Ventricles"
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slug: "asymmetric-lateral-ventricles"
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treeNodeId: null
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category: "Brain"
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||||
cmeTopicId: "5536eb32-54f9-4eb3-83c6-15950dc4efe6"
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documentVersionId: "7b24399c-3ad6-47c3-9521-b6125b27d26d"
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imageCount: 54
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lastUpdated: "01/25/23"
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pageDescription: "Asymmetric Lateral Ventricles"
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pageKeywords: "Brain, Differential Diagnosis, Ventricles, Periventricular Regions, Generic Imaging Patterns, Asymmetric Lateral Ventricles"
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pageTitle: "Asymmetric Lateral Ventricles | STATdx"
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enhancedTitle: "Asymmetric Lateral Ventricles"
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type: "DDX"
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references: true
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breadcrumbs:
|
||||
- "Brain"
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||||
- "Differential Diagnosis"
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||||
- "Ventricles, Periventricular Regions"
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- "Generic Imaging Patterns"
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- "Asymmetric Lateral Ventricles"
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---
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# ESSENTIAL INFORMATION
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- ## Key Differential Diagnosis Issues
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- Asymmetric lateral ventricles are most commonly seen as normal variant
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- ## Helpful Clues for Common Diagnoses
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- **Normal Variant**
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- Asymmetric lateral ventricles seen in 5-10% of normal population
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- Asymmetry mild to moderate, left > right
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- Septum may be displaced across midline
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- No associated mass effect, herniation, or parenchymal atrophy
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- Must exclude parenchymal or intraventricular abnormality
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- **Extrinsic Mass Effect**
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- Etiologies include mass, hemorrhage, infarct, infection
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- Mass can cause ventricular deformity, subfalcine herniation
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- **Encephalomalacia, General**
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- Parenchymal loss results in compensatory ventricular enlargement
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- Common etiologies include chronic infarct, trauma, surgery
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- **Intraventricular Hemorrhage**
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- Involved ventricle may dilate early from mass effect
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- Chronic dilation may be due to scarring and adhesions
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- Etiologies include trauma, arteriovenous malformation (AVM), basal ganglia hemorrhage
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- **Herniation Syndromes, Intracranial**
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- Subfalcine herniation: Cingulate gyrus herniates under falx
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- Ipsilateral lateral ventricle compressed
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- Foramen of Monro obstructs and causes contralateral lateral ventricle enlargement
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- Unilateral descending transtentorial herniation (uncal): Herniation of medial temporal lobe inferiorly
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- Contralateral temporal horn becomes entrapped and enlarges
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- Entrapped ventricle: Typically temporal horn, by extrinsic mass effect
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- **Surgical Defects**
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- Look for calvarial defect or "tract"
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- Typically related to resection of mass
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- Ventricle enlarged unilateral to defect
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- **Obstructive Hydrocephalus**
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- Typically acquired and bilateral
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- May be unilateral if shunt complication or obstructing tumor is cause
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- Rare: Colloid cyst may obstruct unilateral foramen of Monro and cause unilateral ventriculomegaly
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- **Choroid Plexus Cyst**
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- a.k.a. choroid plexus xanthogranuloma
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- Most common choroid plexus mass in adults
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- Nonneoplastic, noninflammatory cyst of choroid plexus
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- Common incidental finding in older patients (40% prevalence)
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- Typically bilateral; may be unilateral and enlarge lateral ventricle
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- Most in lateral ventricular atria
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- 60-80% bright on DWI
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- ## Helpful Clues for Less Common Diagnoses
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- **Ventriculitis**
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- Ventriculomegaly with debris level, enhancing ependyma, periventricular T2/FLAIR hyperintensities
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- May affect lateral ventricles asymmetrically, particularly if related to shunt placement or abscess rupture
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- Restricted diffusion of layering debris is characteristic
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- Bacterial ventriculitis may occur in healthy individuals after trauma or neurosurgical procedure
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- Fungal or viral ventriculitis occurs most commonly in immunosuppressed patients
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- **CSF Shunts and Complications**
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- Common complications include shunt obstruction or breakage, infection, overdrainage
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- Asymmetric ventricles may result from overdrainage or underdrainage of "isolated" ventricle
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- **Meningioma**
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- Although rare, still one of more common intraventricular neoplasms in adults
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- More common in females (F:M = 2:1)
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- Most common location is ventricular atrium with slight majority on left
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- Smooth, avidly enhancing intraventricular mass
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- 50% calcified; cystic changes may be present
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- **Choroid Plexus Papilloma**
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- Enhancing, lobulated intraventricular mass in child
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- 50% in lateral ventricle atrium, left > right
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- 40% in 4th ventricle
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- Increased CSF production in most cases, CSF obstruction in some cases
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- May have CSF spread of tumor
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- **Neurocytoma, Central**
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- Neurocytoma arising from ventricular system, usually septum pellucidum or lateral ventricle
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- Well-circumscribed, lobulated, "bubbly" lesions
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- 50% calcifications, cyst-like areas, enhancement, prominent associated flow voids
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- MRS: Glycine peak (3.55 ppm) may help differentiation from other intraventricular neoplasms
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- **Neurocysticercosis**
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- May involve cisterns > parenchyma > ventricles
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- Intraventricular disease anywhere from 0.7-33% of cases
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- May lead to obstructive hydrocephalus, ventriculitis, adhesions
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- Intraventricular cyst signal intensity may differ slightly from CSF on T1, T2, FLAIR
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- ## Helpful Clues for Rare Diagnoses
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- **Intraventricular Synechiae/Adhesions**
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- May be congenital or acquired (prior bleed, infection, tumor)
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- Look for enhancing septa, intraventricular cysts within ventricle
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- **Choroid Plexus Carcinoma**
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- Enhancing intraventricular mass and ependymal invasion in young child
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- CSF seeding common
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- Imaging does not allow reliable distinction between choroid plexus papilloma and carcinoma
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- May be more heterogeneous than choroid plexus papilloma in part reflecting areas of necrosis
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- May demonstrate elevation of lactate level
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- **Ependymal Cyst**
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- Nonenhancing, thin-walled cyst with CSF density/intensity
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- Lateral ventricle most common location
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- Most are incidental
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- Best diagnostic clue: Nonenhancing, thin-walled CSF density/intensity cyst in lateral ventricle
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- **Dyke-Davidoff-Masson**
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- Antenatal unilateral hemispheric insult causes cerebral hemiatrophy
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- Compensatory ipsilateral calvarial thickening, hyperpneumatized frontal sinuses and temporal bones due to longstanding cerebral hemiatrophy
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- Dilated ventricle from volume loss is ipsilateral to small hemisphere
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- **Hemimegalencephaly**
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- Unilateral hemispheric cortical thickening
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- Dilated, usually dysmorphic ventricle ipsilateral to enlarged hemisphere
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- Ipsilateral extracalvarial soft tissues may be larger
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- Pachygyria, polymicrogyria, heterotopias, abnormal white matter signal, blurring of gray-white matter junction
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- **Rasmussen Encephalitis**
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- Chronic unilateral brain inflammation of uncertain etiology leading to progressive hemispheric atrophy
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- Early focal swelling of gyri
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- Unilateral, predominantly frontoinsular cortical and subcortical T2/FLAIR hyperintensity progress to atrophy
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- ## Other Essential Information
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- High-resolution MR cisternography: CISS, balanced FFE, FIESTA
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- May detect small septations or arachnoid membranes causing obstruction
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- Cine CSF flow study may help detect physiologic flow obstruction from arachnoid webs or membranes
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- May assess adequacy of drainage procedures
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## References
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# Selected References
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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)
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1. [Lanska DJ: Cruveilhier's unrecognized case (c1831) of Dyke-Davidoff-Masson syndrome. Eur Neurol. 84(4):300-6, 2021](http://www.ncbi.nlm.nih.gov/pubmed/?term=33965957%5Bpmid%5D)
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1. [Cay-Martinez KC et al: Rasmussen encephalitis: an update. Semin Neurol. 40(2):201-10, 2020](http://www.ncbi.nlm.nih.gov/pubmed/?term=32185790%5Bpmid%5D)
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1. [Crawford JR et al: Perinatal (fetal and neonatal) choroid plexus tumors: a review. Childs Nerv Syst. 35(6):937-44, 2019](http://www.ncbi.nlm.nih.gov/pubmed/?term=30953158%5Bpmid%5D)
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1. [Tan LA et al: Obstructive hydrocephalus due to intraventricular hemorrhage after incidental durotomy during lumbar spine surgery. Spine (Phila Pa 1976). 43(5):E316-9, 2018](http://www.ncbi.nlm.nih.gov/pubmed/?term=26208226%5Bpmid%5D)
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1. [Zamora CA et al: Teaching neuroImages: Dyke-Davidoff-Masson in Sturge-Weber syndrome. Neurology. 85(16):e128, 2015](http://www.ncbi.nlm.nih.gov/pubmed/?term=26481933%5Bpmid%5D)
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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)
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1. [Kimura-Hayama ET et al: Neurocysticercosis: radiologic-pathologic correlation. Radiographics. 30(6):1705-19, 2010](http://www.ncbi.nlm.nih.gov/pubmed/?term=21071384%5Bpmid%5D)
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1. [Kiroğlu Y et al: Cerebral lateral ventricular asymmetry on CT: how much asymmetry is representing pathology? Surg Radiol Anat. 30(3):249-55, 2008](http://www.ncbi.nlm.nih.gov/pubmed/?term=18253688%5Bpmid%5D)
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1. [Rastogi S et al: Neuroimaging in pediatric epilepsy: a multimodality approach. Radiographics. 28(4):1079-95, 2008](http://www.ncbi.nlm.nih.gov/pubmed/?term=18635630%5Bpmid%5D)
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1. [Osborn AG, Preece MT. Intracranial cysts: radiologic-pathologic correlation and imaging approach. Radiology. 2006 Jun;239(3):650-64.](http://www.ncbi.nlm.nih.gov/pubmed/?term=16714456%5Bpmid%5D)
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1. [Koeller KK et al: Cerebral intraventricular neoplasms: radiologic-pathologic correlation. Radiographics. 22(6):1473-505, 2002](http://www.ncbi.nlm.nih.gov/pubmed/?term=12432118%5Bpmid%5D)
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## Images
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### Selected Images
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**Normal Variant**
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*Axial T2 MR demonstrates normal variant anatomy with mild asymmetric prominence of the right lateral ventricle <img src='/img/arrows/CO.png'/> when compared to the left. Note the septum is slightly deviated to the left <img src='/img/arrows/CS.png'/>.*
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**Normal Variant**
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*Axial T2 MR demonstrates normal variant anatomy with mild asymmetric prominence of the right lateral ventricle <img src='/img/arrows/CO.png'/> when compared to the left. Note the septum is slightly deviated to the left <img src='/img/arrows/CS.png'/>.*
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**Extrinsic Mass Effect**
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*Axial FLAIR MR demonstrates a large, heterogeneous mass in the left frontal lobe <img src='/img/arrows/CS.png'/> with surrounding edema and mass effect with compression of the left lateral ventricle <img src='/img/arrows/CO.png'/> and moderate dilation of the right lateral ventricle <img src='/img/arrows/CC.png'/>.*
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**Encephalomalacia, General**
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*Axial T2 MR demonstrates a large, cystic encephalomalacia in the left frontal and parietal lobes due to chronic infarction <img src='/img/arrows/CC.png'/> with ex-vacuo dilation of the left lateral ventricle <img src='/img/arrows/CS.png'/>.*
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**Intraventricular Hemorrhage**
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*Axial T2 MR demonstrates a large amount of acute intraventricular hemorrhage with mild dilation of the right lateral ventricle <img src='/img/arrows/CS.png'/>. Note CSF seepage in the peritrigonal region <img src='/img/arrows/CC.png'/>.*
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**Herniation Syndromes, Intracranial**
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*Axial NECT demonstrates a large left subdural hematoma <img src='/img/arrows/BS.png'/> and a small parenchymal hemorrhage <img src='/img/arrows/BO.png'/>, resulting in rightward subfalcine herniation <img src='/img/arrows/CS.png'/>, compression of the left lateral ventricle <img src='/img/arrows/CO.png'/>, and mild dilation of the right lateral ventricle <img src='/img/arrows/CC.png'/>.*
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**Surgical Defects**
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*Axial FLAIR MR demonstrates a large surgical defect in the left frontal lobe <img src='/img/arrows/CO.png'/> due to a tumor resection with resultant mild prominence of the left lateral ventricle <img src='/img/arrows/CS.png'/>.*
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**Obstructive Hydrocephalus**
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*Axial T1 C+ MR demonstrates enhancing intraventricular mass <img src='/img/arrows/CS.png'/> with obstructive dilation of the left temporal horn <img src='/img/arrows/CO.png'/>.*
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**CSF Shunts and Complications**
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*Axial T2 MR demonstrates a shunt catheter in the right lateral ventricle <img src='/img/arrows/CS.png'/> with asymmetric lateral ventricles due to overdrainage of the right <img src='/img/arrows/CO.png'/> and mild underdrainage of the left <img src='/img/arrows/CC.png'/>. Note susceptibility artifact <img src='/img/arrows/WS.png'/> due to the shunt reservoir.*
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**Meningioma**
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*Axial T2 MR demonstrates a left lateral intraventricular isointense mass <img src='/img/arrows/CO.png'/> in the trigone with dilatation of the left trigone <img src='/img/arrows/CS.png'/>. Note periventricular edema <img src='/img/arrows/CC.png'/>. Biopsy revealed meningioma.*
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**Neurocytoma, Central**
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*Axial T2 MR demonstrates a well-circumscribed, isointense, left lateral ventricular mass <img src='/img/arrows/CS.png'/> attached to the septum pellucidum with peripheral tiny cysts <img src='/img/arrows/CC.png'/>. Note moderate dilation of the left lateral ventricle <img src='/img/arrows/CO.png'/>. Biopsy revealed neurocytoma.*
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**Intraventricular Synechiae/Adhesions**
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*Coronal T2 MR demonstrates asymmetric mild enlargement of the left lateral ventricle <img src='/img/arrows/CO.png'/> due to synechiae <img src='/img/arrows/CS.png'/> obstructing the foramen of Monro.*
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**Choroid Plexus Carcinoma**
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*Axial T2 MR demonstrates a poorly circumscribed heterogeneous left trigonal mass <img src='/img/arrows/CO.png'/> with internal cysts/necrosis. Note extensive periventricular edema <img src='/img/arrows/CC.png'/>. Biopsy revealed choroid plexus carcinoma.*
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**Dyke-Davidoff-Masson**
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*Axial NECT demonstrates atrophy of the left cerebral hemisphere with encephalomalacia due to antenatal vascular insult. Note the dilated left lateral ventricle <img src='/img/arrows/CS.png'/> and mild overlying calvarial thickening <img src='/img/arrows/CO.png'/>.*
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**Rasmussen Encephalitis**
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*Axial T2 MR in a patient with refractory epilepsy due to Rasmussen encephalitis demonstrates left cerebral hemispheric atrophy <img src='/img/arrows/CC.png'/> and mild ex-vacuo dilation of the left lateral ventricle <img src='/img/arrows/CS.png'/>.*
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### Additional Images
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**Extrinsic Mass Effect**
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*Axial T1WI C+ MR shows compression of the left frontal horn <img src='/img/arrows/WS.png'/> by a large, periventricular, enhancing mass <img src='/img/arrows/WC.png'/>, primary CNS lymphoma. Extrinsic mass effect is a common cause of ventricular asymmetry.*
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**Encephalomalacia, General**
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*Axial FLAIR MR demonstrates a left posterior MCA encephalomalacia <img src='/img/arrows/WS.png'/> resulting in mild ex-vacuo dilatation of the left atrium <img src='/img/arrows/WO.png'/>.*
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**Encephalomalacia, General**
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*Axial T2 MR shows right hemiatrophy in Sturge-Weber syndrome. Chronic venous ischemia leads to progressive hemiatrophy. Note the ipsilateral large right ventricle <img src='/img/arrows/WO.png'/> due to volume loss.*
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**Intraventricular Hemorrhage**
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*Axial NECT shows a basal ganglia hypertensive hemorrhage <img src='/img/arrows/WS.png'/> with intraventricular extension <img src='/img/arrows/WO.png'/>. Associated midline shift results in dilation of the contralateral ventricles <img src='/img/arrows/WC.png'/> from foramen of Monro obstruction.*
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**Herniation Syndromes, Intracranial**
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*Coronal FLAIR MR shows a diffusely enlarged hyperintense supratentorial cortex <img src='/img/arrows/WS.png'/> compared to the cerebellum in this patient in longstanding status epilepticus. Disproportionate left hemisphere involvement has resulted in left ventricular compression <img src='/img/arrows/WO.png'/>, right foramen of Monro outlet obstruction, and dilation of the right ventricular system <img src='/img/arrows/WC.png'/>.*
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**Herniation Syndromes, Intracranial**
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*Coronal T1WI C+ MR shows a right hemispheric, subacute, subdural hematoma causing subfalcine <img src='/img/arrows/WC.png'/> and uncal <img src='/img/arrows/WO.png'/> herniation. Mass effect compresses the right frontal horn. The left ventricle <img src='/img/arrows/BO.png'/> is enlarged from foramen of Monro obstruction.*
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**Herniation Syndromes, Intracranial**
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*Coronal T2WI MR shows right temporal viral encephalitis causing local mass effect <img src='/img/arrows/WO.png'/>. The left lateral ventricle <img src='/img/arrows/WS.png'/> is larger from foramen of Monro obstruction due to midline shift.*
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**Surgical Defects**
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*Axial T2WI MR shows widening of right foramen of Monro <img src='/img/arrows/WS.png'/>, septum pellucidum deviation <img src='/img/arrows/BS.png'/>, and an enlarged right lateral ventricle <img src='/img/arrows/WO.png'/> in this tuberous sclerosis patient with remote tumor resection.*
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**Obstructive Hydrocephalus**
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*Axial NECT shows marked enlargement of the left lateral ventricle with bowing of septum pellucidum across midline <img src='/img/arrows/WS.png'/> and transependymal CSF migration <img src='/img/arrows/WO.png'/> indicating acute obstruction. Findings were related to a small atrial diverticulum.*
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**Obstructive Hydrocephalus**
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*Axial T1WI C+ MR shows a colloid cyst <img src='/img/arrows/WS.png'/> believed to be complicated by inflammatory changes. Obstruction of the left foramen of Monro causes unilateral left lateral ventricle dilation <img src='/img/arrows/WO.png'/>.*
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**Obstructive Hydrocephalus**
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*Axial T2WI MR shows a medial atrial diverticulum <img src='/img/arrows/WS.png'/>, a rare complication of severe hydrocephalus. CSF pouch herniates inferomedially through tentorial incisura.*
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**Obstructive Hydrocephalus**
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*Coronal T1WI C+ MR shows typical case of coccidioidomycosis meningitis. Note marked enhancement of basal cisterns <img src='/img/arrows/BS.png'/> and asymmetric ventricular enlargement <img src='/img/arrows/WS.png'/> from CSF obstruction.*
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**Choroid Plexus Cyst**
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*Axial T1WI C+ MR shows a lobulated, nonenhancing mass <img src='/img/arrows/WS.png'/> in the lateral ventricle atrium, a choroid plexus xanthogranuloma. This degenerative cyst of the choroid plexus is often found incidentally in older patients.*
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**Ventriculitis**
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*Axial T1WI C+ MR shows ventriculitis with asymmetric lateral ventricles related to a temporal lobe abscess <img src='/img/arrows/WS.png'/> rupture and meningitis <img src='/img/arrows/WC.png'/>. Note ventriculomegaly and ventricular wall enhancement <img src='/img/arrows/WO.png'/> characteristic of ventriculitis.*
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**Ventriculitis**
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*Axial CECT shows marked ventriculomegaly and ependymal enhancement <img src='/img/arrows/WS.png'/>. A dependent debris level <img src='/img/arrows/WC.png'/> is noted in both lateral ventricles. Ventriculitis has resulted from abscess <img src='/img/arrows/WO.png'/> rupture.*
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**CSF Shunts and Complications**
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*Axial NECT shows an infant with hydrocephalus after placement of a right frontal ventricular drain <img src='/img/arrows/WS.png'/>. The shunt did not cross midline. The left lateral ventricle remained enlarged, and the right became slit-like.*
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**CSF Shunts and Complications**
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*Axial T2WI MR shows marked enlargement of the isolated right lateral ventricle with transependymal flow of CSF <img src='/img/arrows/WC.png'/> indicating acute obstruction. Note left shunt <img src='/img/arrows/WS.png'/> and completely decompressed left lateral ventricle.*
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||||
|
||||
|
||||
**CSF Shunts and Complications**
|
||||
*Axial NECT shows asymmetric left ventricular dilation <img src='/img/arrows/WS.png'/> post shunting <img src='/img/arrows/WO.png'/>. Shunt tip may be occluded from clot <img src='/img/arrows/WC.png'/> or from imperforate septum, preventing drainage of the left ventricular system.*
|
||||
|
||||
|
||||
**Meningioma**
|
||||
*Axial T2WI FS MR shows a hypointense choroid plexus mass <img src='/img/arrows/WS.png'/> in the atrium of the left lateral ventricle that enhanced intensely (not shown). Note striking surrounding vasogenic edema <img src='/img/arrows/WC.png'/> in adjacent brain parenchyma, thought due to locally obstructed CSF.*
|
||||
|
||||
|
||||
**Neurocytoma, Central**
|
||||
*Axial T1WI C+ MR demonstrates a mildly enhancing and heterogeneous mass arising from the septum pellucidum <img src='/img/arrows/WS.png'/>. Note asymmetric dilatation of the right lateral ventricle <img src='/img/arrows/WO.png'/>.*
|
||||
|
||||
|
||||
**Choroid Plexus Papilloma**
|
||||
*Axial T1WI C+ MR shows enhancement within the mass in the atrium of the lateral ventricle <img src='/img/arrows/WS.png'/> with an encysted asymmetrically larger left lateral ventricle.*
|
||||
|
||||
|
||||
**Neurocysticercosis**
|
||||
*Axial T1WI C+ MR shows asymmetric lateral ventricles caused by a giant neurocysticercosis cyst <img src='/img/arrows/WS.png'/> in the body of the left lateral ventricle.*
|
||||
|
||||
|
||||
**Intraventricular Synechiae/Adhesions**
|
||||
*Axial T1WI C+ FS MR shows a large mass in the atrium of the right lateral ventricle <img src='/img/arrows/WC.png'/> with a trapped, encysted occipital horn <img src='/img/arrows/WO.png'/>. Ependymal enhancement represents tumor spread from choroidal metastasis.*
|
||||
|
||||
|
||||
**Dyke-Davidoff-Masson**
|
||||
*Axial T1WI C+ MR shows an asymmetrically larger right atrium <img src='/img/arrows/WS.png'/> in this patient with Sturge-Weber syndrome. Note associated ipsilateral enlarged frontal sinus <img src='/img/arrows/BO.png'/> and calvarial thickening <img src='/img/arrows/BC.png'/>.*
|
||||
|
||||
|
||||
**Hemimegalencephaly**
|
||||
*Axial CECT shows enlargement of the right hemisphere and lateral ventricle <img src='/img/arrows/WS.png'/> compared to the left side. Expansion of the hemisphere is mostly due to increased white matter. An enlarged, often deformed, lateral ventricle on the abnormal side is typical.*
|
||||
|
||||
|
||||
**Ependymal Cyst**
|
||||
*Axial FLAIR MR shows a cyst enlarging the left lateral ventricle with signal intensity isointense to CSF <img src='/img/arrows/WS.png'/>. There was no enhancement of the cyst wall, typical of ependymal cyst.*
|
||||
|
||||
|
||||
**Ependymal Cyst**
|
||||
*Axial FLAIR MR shows a cystic lesion arising from the ependymal lining of the left temporal horn <img src='/img/arrows/CS.png'/>, consistent with an ependymal cyst. The lesion followed CSF signal on every sequence.*
|
||||
|
||||
|
||||
**CSF Shunts and Complications**
|
||||
*Axial T1WI MR demonstrates a right parietal shunt catheter with its tip <img src='/img/arrows/WS.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.*
|
||||
|
||||
|
||||
**Ventriculitis**
|
||||
*Axial T1WI C+ MR shows ependymal enhancement and mild asymmetric dilatation of the left occipital horn <img src='/img/arrows/CO.png'/> in ventriculitis. There is also asymmetric enhancement of the adjacent choroid plexus consistent with choroid plexitis <img src='/img/arrows/WO.png'/>.*
|
||||
|
||||
|
||||
**Choroid Plexus Cyst**
|
||||
*Axial T2WI MR shows a large, hyperintense choroid plexus cyst <img src='/img/arrows/CS.png'/> in a newborn. The lesion increased in size on sequential imaging, requiring endoscopic fenestration.*
|
||||
|
||||
|
||||
**Surgical Defects**
|
||||
*Axial FLAIR MR shows asymmetric dilatation of the left frontal horn <img src='/img/arrows/CS.png'/> and surrounding gliosis following the resection of an intraaxial metastasis. Part of the surgical tract is seen <img src='/img/arrows/CO.png'/>. Note multiple additional metastatic lesions <img src='/img/arrows/WS.png'/> in the right cerebral hemisphere.*
|
||||
|
||||
|
||||
**Herniation Syndromes, Intracranial**
|
||||
*Axial NECT demonstrates a large left frontal intraparenchymal hematoma <img src='/img/arrows/BO.png'/> causing subfalcine herniation to the right <img src='/img/arrows/CS.png'/>. The left lateral ventricle is effaced. The posterior right lateral ventricle is mildly dilated <img src='/img/arrows/CO.png'/>.*
|
||||
|
||||
|
||||
**Intraventricular Hemorrhage**
|
||||
*Axial NECT shows a large amount of intraventricular hemorrhage <img src='/img/arrows/CS.png'/> resulting in moderate asymmetric expansion of the left lateral ventricle. A smaller amount of layering blood products is seen in the right lateral ventricle <img src='/img/arrows/CO.png'/>.*
|
||||
|
||||
|
||||
**Rasmussen Encephalitis**
|
||||
*Axial T2WI MR shows mild, asymmetric, right hemispheric volume loss with prominent sulci <img src='/img/arrows/CS.png'/> and mild, asymmetric, right lateral ventricle dilatation <img src='/img/arrows/CO.png'/> in a pediatric patient with Rasmussen encephalitis.*
|
||||
|
||||
|
||||
**Extrinsic Mass Effect**
|
||||
*Axial FLAIR MR shows a round mass in the right occipital lobe <img src='/img/arrows/CS.png'/> (primary CNS lymphoma) that effaces the adjacent right occipital horn and atrium <img src='/img/arrows/CO.png'/>. Extrinsic mass effect is a common cause of ventricular asymmetry and compression.*
|
||||
|
||||
|
||||
**Neurocytoma, Central**
|
||||
*Axial T1WI C+ MR demonstrates a heterogeneous enhancing mass <img src='/img/arrows/CS.png'/> arising from the septum pellucidum, a pathologically proven central neurocytoma. Note moderate asymmetric dilatation of the right lateral ventricle <img src='/img/arrows/CO.png'/>.*
|
||||
|
||||
|
||||
**Obstructive Hydrocephalus**
|
||||
*Axial FLAIR MR shows a left thalamic expansile mass <img src='/img/arrows/CS.png'/>, a glioblastoma, which demonstrated heterogeneous enhancement (not shown). It protrudes into and obstructs the left ventricular atrium, which is asymmetrically dilated <img src='/img/arrows/CO.png'/>.*
|
||||
|
||||
|
||||
**Encephalomalacia, General**
|
||||
*Axial T2WI MR demonstrates generalized left hemispheric encephalomalacia <img src='/img/arrows/CS.png'/> following necrotizing encephalitis of unknown origin. There is resultant mild ex-vacuo dilatation of the left lateral ventricle <img src='/img/arrows/CO.png'/>.*
|
||||
|
||||
|
||||
**Meningioma**
|
||||
*Axial T1WI C+ MR shows an avidly enhancing, lobulated mass arising from the right ventricular atrium <img src='/img/arrows/CS.png'/>, a meningioma. Note the mild asymmetric dilatation of the left lateral ventricle <img src='/img/arrows/CO.png'/>.*
|
||||
|
||||
|
||||
**Normal Variant**
|
||||
*Axial T2WI MR shows lateral ventricles with the right <img src='/img/arrows/CS.png'/> being larger than the left, representing a normal variant. Note mild bowing of the septum pellucidum across the midline <img src='/img/arrows/CC.png'/>.*
|
||||
|
||||
Reference in New Issue
Block a user