316 lines
17 KiB
Markdown
316 lines
17 KiB
Markdown
---
|
|
title: "Cavum Velum Interpositum (CVI)"
|
|
docid: "849ee468-35c4-46e3-9297-96196109cdb8"
|
|
authors:
|
|
- key: "a25c450b-3d34-4f64-bba3-cc0834813df6"
|
|
value: "Miral D. Jhaveri, MD, MBA"
|
|
- key: "5cff4116-3654-4b3a-bb75-5ebe0b8c9850"
|
|
value: "Anne G. Osborn, MD, FACR"
|
|
breadcrumbs:
|
|
-
|
|
name: "Brain"
|
|
slug: "brain"
|
|
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
|
|
-
|
|
name: "Diagnosis"
|
|
slug: "diagnosis"
|
|
treeNodeId: "51c00394-446e-4a38-94af-d3b1d14d34e8"
|
|
-
|
|
name: "Anatomy-Based Diagnoses"
|
|
slug: "anatomy-based-diagnoses"
|
|
treeNodeId: "529d3e33-f508-498c-bc70-cf962e81e629"
|
|
-
|
|
name: "Ventricles and Cisterns"
|
|
slug: "ventricles-and-cisterns"
|
|
treeNodeId: "33b267f0-908c-4c77-81f8-f6135d1bc592"
|
|
-
|
|
name: "Normal Variants"
|
|
slug: "normal-variants"
|
|
treeNodeId: "bf92256f-cdff-4bcd-8420-d876b9e4031a"
|
|
-
|
|
name: "Cavum Velum Interpositum (CVI)"
|
|
slug: "cavum-velum-interpositum-cvi"
|
|
treeNodeId: null
|
|
category: "Brain"
|
|
documentVersionId: "75312185-3ddd-4300-a4fb-d824b606effc"
|
|
imageCount: 12
|
|
lastUpdated: "05/08/20"
|
|
pageDescription: "Cavum Velum Interpositum (CVI)"
|
|
pageKeywords: "Brain, Diagnosis, Anatomy-Based Diagnoses, Ventricles and Cisterns, Normal Variants, Cavum Velum Interpositum (CVI)"
|
|
pageTitle: "Cavum Velum Interpositum (CVI) | STATdx"
|
|
enhancedTitle: "Cavum Velum Interpositum (CVI)"
|
|
type: "DX"
|
|
references: true
|
|
breadcrumbs:
|
|
- "Brain"
|
|
- "Diagnosis"
|
|
- "Anatomy-Based Diagnoses"
|
|
- "Ventricles and Cisterns"
|
|
- "Normal Variants"
|
|
- "Cavum Velum Interpositum (CVI)"
|
|
---
|
|
# KEY FACTS
|
|
|
|
- ## Terminology
|
|
|
|
|
|
- Cavum velum interpositum (CVI), cyst of velum interpositum (VI)
|
|
- ## Imaging
|
|
|
|
|
|
- Triangular CSF space
|
|
- Between lateral ventricles, over thalami
|
|
- Apex points toward foramen of Monro
|
|
- Elevates, splays fornices
|
|
- Flattens, displaces internal cerebral veins inferiorly
|
|
- Size varies from slit-like linear to triangular to round/ovoid CSF collection
|
|
- Isodense/isointense with CSF
|
|
- Suppresses completely on FLAIR
|
|
- Does not restrict on DWI
|
|
- Does not enhance
|
|
- US shows hypoechoic midline interhemispheric cyst
|
|
- ## Top Differential Diagnoses
|
|
|
|
|
|
- Normal cistern of velum interpositum
|
|
- Cavum septi pellucidi, cavum vergae
|
|
- Arachnoid cyst
|
|
- Epidermoid cyst
|
|
- ## Clinical Issues
|
|
|
|
|
|
- Can be found at any age
|
|
- Common in infants, rare in adults
|
|
- Symptoms
|
|
- Usually asymptomatic, found incidentally
|
|
- Headache (relationship to cyst unclear)
|
|
- Large CVI can obstruct normal CSF flow; treated by endoscopic fenestration
|
|
- ## Diagnostic Checklist
|
|
|
|
|
|
- CSF-like "cyst" could be epidermoid
|
|
- Include FLAIR and DWI to distinguish between CVI, epidermoid cyst
|
|
|
|
# TERMINOLOGY
|
|
|
|
- ## Abbreviations
|
|
|
|
|
|
- Cavum velum interpositum (CVI), cyst of velum interpositum (VI)
|
|
- ## Definitions
|
|
|
|
|
|
- Cystic dilation of VI
|
|
|
|
# IMAGING
|
|
|
|
- ## General Features
|
|
|
|
|
|
- ### Best diagnostic clue
|
|
|
|
|
|
- Triangular-shaped CSF space
|
|
- Between lateral ventricles, over thalami
|
|
- Apex points toward but does not extend anteriorly beyond foramen of Monro
|
|
- Base contiguous with quadrigeminal cistern
|
|
- ### Location
|
|
|
|
|
|
- Midline between lateral ventricles, below fornices
|
|
- Continuous with choroid plexus subependymally
|
|
- ### Size
|
|
|
|
|
|
- Varies (few mm to several cm)
|
|
- ## CT Findings
|
|
|
|
|
|
- ### NECT
|
|
|
|
|
|
- Triangle of CSF between lateral ventricles
|
|
- ### CECT
|
|
|
|
|
|
- Does not enhance
|
|
- ## MR Findings
|
|
|
|
|
|
- ### T1WI
|
|
|
|
|
|
- Sagittal: Varies from slit-like linear to round/ovoid
|
|
- Elevates fornices
|
|
- Flattens, displaces internal cerebral veins inferiorly
|
|
- Axial: Triangle of CSF between lateral ventricles
|
|
- ### T2WI
|
|
|
|
|
|
- Isointense with CSF
|
|
- ### FLAIR
|
|
|
|
|
|
- Suppresses completely
|
|
- ### DWI
|
|
|
|
|
|
- Does not restrict
|
|
- ## Ultrasonographic Findings
|
|
|
|
|
|
- ### Color Doppler
|
|
|
|
|
|
- Hypoechoic midline interhemispheric cyst
|
|
- ## Imaging Recommendations
|
|
|
|
|
|
- ### Best imaging tool
|
|
|
|
|
|
- MR ± contrast
|
|
- ### Protocol advice
|
|
|
|
|
|
- FLAIR/DWI (distinguish between CVI and epidermoid)
|
|
|
|
# DIFFERENTIAL DIAGNOSIS
|
|
|
|
- [Normal Cistern of Velum Interpositum](/document/pineal-cyst/eda99e5c-c992-4798-aa35-21437eb505ea)
|
|
- Usually small (slit-like or oval)
|
|
- Does not elevate fornices or depress internal cerebral veins
|
|
- ## Cavum Septi Pellucidi, Vergae
|
|
|
|
|
|
- CSP + CV elongated, finger-like CSF space
|
|
- [Arachnoid Cyst](/document/arachnoid-cyst/7d63f0d3-6999-4d8c-a41d-953f738c43a6)
|
|
- Lined with arachnoid (may be indistinguishable)
|
|
- [Epidermoid Cyst](/document/epidermoid-cyst/704c5ddf-e1f7-4a5d-a1b8-5b0e603170d9)
|
|
- Lobulated, insinuating mass
|
|
- Does not suppress with FLAIR; DWI shows restriction
|
|
|
|
# PATHOLOGY
|
|
|
|
- ## General Features
|
|
|
|
|
|
- ### Etiology
|
|
|
|
|
|
- Pia infolds along transverse fissure, forms CSF cistern (VI)
|
|
- Cystic dilatation of VI may occur (precise etiology unknown)
|
|
- ### Associated abnormalities
|
|
|
|
|
|
- Usually none (large CVIs may cause hydrocephalus)
|
|
- ## Gross Pathologic & Surgical Features
|
|
|
|
|
|
- Normal cistern of VI is small to inapparent at autopsy
|
|
- Pial-lined CSF-filled space
|
|
- ## Microscopic Features
|
|
|
|
|
|
- Occasionally cysts of midline CSF spaces contain glial cells, scattered neurons
|
|
|
|
# CLINICAL ISSUES
|
|
|
|
- ## Presentation
|
|
|
|
|
|
- ### Most common signs/symptoms
|
|
|
|
|
|
- Usually asymptomatic, found incidentally
|
|
- Headache (relationship to cyst unclear)
|
|
- ## Demographics
|
|
|
|
|
|
- ### Age
|
|
|
|
|
|
- Can be found at any age
|
|
- Common in infants, rare in adults
|
|
- ### Gender
|
|
|
|
|
|
- M = F
|
|
- ## Treatment
|
|
|
|
|
|
- Usually none
|
|
|
|
# DIAGNOSTIC CHECKLIST
|
|
|
|
- ## Consider
|
|
|
|
|
|
- CSF-like "cyst" could be epidermoid
|
|
- Use DWI, FLAIR to differentiate from other cysts
|
|
|
|
806ab3b4-9c9a-4887-a52d-d5809cd5a417
|
|
|
|
## References
|
|
|
|
# Selected References
|
|
|
|
1. [Krejčí T et al: Symptomatic cysts of the cavum septi pellucidi, cavum vergae and cavum veli interpositi: A retrospective duocentric study of 10 patients. Clin Neurol Neurosurg. 185:105494, 2019](http://www.ncbi.nlm.nih.gov/pubmed/?term=31472394%5Bpmid%5D)
|
|
1. [Akinola RA et al: Caval variations in neurologically diseased patients. Acta Radiol Short Rep. 3(5):2047981614530288, 2014](http://www.ncbi.nlm.nih.gov/pubmed/?term=25298867%5Bpmid%5D)
|
|
1. [Tong CK et al: Endoscopic fenestration of cavum velum interpositum cysts: a case study of two symptomatic patients. Childs Nerv Syst. 28(8):1261-4, 2012](http://www.ncbi.nlm.nih.gov/pubmed/?term=22543434%5Bpmid%5D)
|
|
1. [Tubbs RS et al: Cavum velum interpositum, cavum septum pellucidum, and cavum vergae: a review. Childs Nerv Syst. 27(11):1927-30, 2011](http://www.ncbi.nlm.nih.gov/pubmed/?term=21687999%5Bpmid%5D)
|
|
1. [Tubbs RS et al: The velum interpositum revisited and redefined. Surg Radiol Anat. 30(2):131-5, 2008](http://www.ncbi.nlm.nih.gov/pubmed/?term=18094919%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. [Eisenberg VH et al: Prenatal diagnosis of cavum velum interpositum cysts: significance and outcome. Prenat Diagn. 23(10):779-83, 2003](http://www.ncbi.nlm.nih.gov/pubmed/?term=14558018%5Bpmid%5D)
|
|
1. [Vergani P et al: Ultrasonographic differential diagnosis of fetal intracranial interhemispheric cysts. Am J Obstet Gynecol. 180(2 Pt 1):423-8, 1999](http://www.ncbi.nlm.nih.gov/pubmed/?term=9988813%5Bpmid%5D)
|
|
1. [Chen CY et al: Sonographic characteristics of the cavum velum interpositum. AJNR Am J Neuroradiol. 19(9):1631-5, 1998](http://www.ncbi.nlm.nih.gov/pubmed/?term=9802483%5Bpmid%5D)
|
|
|
|
|
|
## Images
|
|
|
|
|
|
### Selected Images
|
|
|
|
|
|
*Sagittal graphic with axial insert shows a cavum velum interpositum (CVI). Note the elevation and splaying of the fornices <img src='img/arrows/WO.png'/>. Also noted is the inferior displacement of the internal cerebral veins and 3rd ventricle <img src='img/arrows/WS.png'/>.*
|
|
|
|
|
|
*Sagittal graphic with axial insert shows a cavum velum interpositum (CVI). Note the elevation and splaying of the fornices <img src='img/arrows/WO.png'/>. Also noted is the inferior displacement of the internal cerebral veins and 3rd ventricle <img src='img/arrows/WS.png'/>.*
|
|
|
|
|
|
*Sagittal T1 MR shows a classic CVI <img src='img/arrows/CC.png'/> as a CSF-like enlargement that elevates the fornix <img src='img/arrows/CS.png'/> and flattens and displaces the internal cerebral vein <img src='img/arrows/CO.png'/> inferiorly. These are usually asymptomatic; however, large ones can cause CSF obstruction and can be treated by fenestration.*
|
|
|
|
|
|
*Axial T2 MR in a 37-year-old man with headaches shows a triangular-shaped CSF collection <img src='img/arrows/CS.png'/> between the lateral ventricles, spreading the fornices laterally <img src='img/arrows/CC.png'/>.*
|
|
|
|
|
|
*Axial FLAIR MR in the same patient shows complete suppression of the CSF signal within the cyst <img src='img/arrows/CC.png'/> similar to the lateral ventricles. Findings are consistent with a classic cavum velum interpositum. FLAIR and DWI distinguish between cavum velum interpositum and an epidermoid cyst.*
|
|
|
|
|
|
### Additional Images
|
|
|
|
|
|
*Axial T2 MR shows a cavum septi pellucidi (CSP) <img src='img/arrows/BO.png'/> along with a very small cavum velum interpositum <img src='img/arrows/BS.png'/>. Note that these 2 unrelated lesions do not communicate with each other. It is common to see a CSP with a cavum vergae; it is rare to see a CSP and a CVI in the same patient.*
|
|
|
|
|
|
*Coronal T1 C+ MR shows classic cavum velum interpositum <img src='img/arrows/CO.png'/> that spreads the fornices <img src='img/arrows/CS.png'/> apart.*
|
|
|
|
|
|
*Axial T2 MR shows a small, triangular-shaped CSF space. Note the cavum velum interpositum <img src='img/arrows/CO.png'/> interposed between the fornices <img src='img/arrows/BS.png'/> and lateral ventricles. The CVI ends at the foramen of Monro.*
|
|
|
|
|
|
*Axial T1 MR shows a very large cavum velum interpositum. Note the splaying of fornices <img src='img/arrows/WS.png'/> and anterior displacement of the septum pellucidum <img src='img/arrows/WO.png'/>. Mild enlargement of the lateral ventricles is seen.*
|
|
|
|
|
|
*Sagittal T1 MR in the same patient shows anterior/superior displacement of the fornix <img src='img/arrows/CC.png'/> and inferior displacement of the 3rd ventricle <img src='img/arrows/CO.png'/>. The corpus callosum is elevated and thinned.*
|
|
|
|
|
|
*Sagittal T1 MR in a 40-year-old woman with headaches shows CSF-like enlargement of the velum interpositum <img src='img/arrows/BC.png'/> that elevates the fornix <img src='img/arrows/BS.png'/> and flattens and displaces the internal cerebral vein inferiorly <img src='img/arrows/BO.png'/>. This large CVI is probably unrelated to the patient's symptoms.*
|
|
|
|
|
|
*Axial T2 MR in a 46-year-old woman with headaches shows a classic CVI with a triangular-shaped CSF collection <img src='img/arrows/WO.png'/>, spreading the fornices laterally <img src='img/arrows/WS.png'/>. The posterior location between the lateral ventricles is typical.*
|
|
|
|
|
|
*Sagittal T1 MR shows a variant CVI <img src='img/arrows/CS.png'/> that elevates the fornix <img src='img/arrows/BS.png'/>, flattens the internal cerebral vein <img src='img/arrows/CC.png'/>, and extends into the quadrigeminal and suprasellar cisterns <img src='img/arrows/CO.png'/>. This case probably represents an arachnoid cyst of the cavum velum interpositum.*
|
|
|