ross/statdx
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
0bd27c271457d496f513541785a56d5c5bea3af0
statdx/docs_md/articles/extracranial-veins_83693722-9b65-4d3c-8f5b-88c9824b4252.md
T
Ross 460ea1af57 update
2026-07-07 17:25:06 +01:00

18 KiB
Raw Blame History

title, docid, authors, breadcrumbs, category, documentVersionId, imageCount, lastUpdated, pageDescription, pageKeywords, pageTitle, enhancedTitle, type, breadcrumbs
title docid authors breadcrumbs category documentVersionId imageCount lastUpdated pageDescription pageKeywords pageTitle enhancedTitle type breadcrumbs
Extracranial Veins 83693722-9b65-4d3c-8f5b-88c9824b4252
key value
5cff4116-3654-4b3a-bb75-5ebe0b8c9850 Anne G. Osborn, MD, FACR
name slug treeNodeId
Brain brain 0361042c-9c90-48e4-864e-a2e6428ee9c9
name slug treeNodeId
Anatomy anatomy a686f22f-27cc-457e-9479-2ef35e94647f
name slug treeNodeId
Veins and Venous Sinuses veins-and-venous-sinuses 63efb008-a516-40be-acaf-ad8e75fbee8b
name slug treeNodeId
Extracranial Veins extracranial-veins null
Brain 2bc8e250-745b-4826-a066-8accb075174f 21 10/20/20 Extracranial Veins Brain, Anatomy, Veins and Venous Sinuses, Extracranial Veins Extracranial Veins | STATdx Extracranial Veins ANATOMY
Brain
Anatomy
Veins and Venous Sinuses
Extracranial Veins

title: "Extracranial Veins" docid: "83693722-9b65-4d3c-8f5b-88c9824b4252" authors:

  • key: "5cff4116-3654-4b3a-bb75-5ebe0b8c9850" value: "Anne G. Osborn, MD, FACR" breadcrumbs:
  • name: "Brain" slug: "brain" treeNodeId: "0361042c-9c90-48e4-864e-a2e6428ee9c9"
  • name: "Anatomy" slug: "anatomy" treeNodeId: "a686f22f-27cc-457e-9479-2ef35e94647f"
  • name: "Veins and Venous Sinuses" slug: "veins-and-venous-sinuses" treeNodeId: "63efb008-a516-40be-acaf-ad8e75fbee8b"
  • name: "Extracranial Veins" slug: "extracranial-veins" treeNodeId: null category: "Brain" documentVersionId: "2bc8e250-745b-4826-a066-8accb075174f" imageCount: 21 lastUpdated: "10/20/20" pageDescription: "Extracranial Veins" pageKeywords: "Brain, Anatomy, Veins and Venous Sinuses, Extracranial Veins" pageTitle: "Extracranial Veins | STATdx" enhancedTitle: "Extracranial Veins" type: "ANATOMY" breadcrumbs:
  • "Brain"
  • "Anatomy"
  • "Veins and Venous Sinuses"
  • "Extracranial Veins"

TERMINOLOGY

  • Abbreviations

    • Internal jugular vein (IJV)
    • Internal carotid artery (ICA)
    • Common carotid artery (CCA)
    • Inferior, superior ophthalmic veins (IOV, SOV)
    • Cavernous sinus (CS)

  • Definitions

    • Extracranial veins include scalp, skull (diploic), face, neck veins

GROSS ANATOMY

  • Overview

    • Scalp veins connect via emissary veins to cranial dural sinuses - Superficial temporal vein collects numerous scalp, auricular tributaries - Descends into parotid space - Together with maxillary vein forms retromandibular vein
    • Diploic veins - Large, irregular endothelial-lined channels in diploic spaces of calvarium - May form large venous "lakes" - Connect freely with dural sinuses, meningeal veins
    • Emissary veins connect intra- and extracranial veins - Traverse cranial apertures, foramina - Connect venous sinuses, extracranial veins - Highly variable
    • Orbital veins (2 major) - SOV connects face/orbit with CS - IOV is smaller, less conspicuous
    • Facial veins - Facial vein - Begins at angle between eye, nose - Descends across masseter, curves around mandible - Joins IJV at hyoid level - Tributaries from orbit (supraorbital, superior ophthalmic veins), lips, jaw, facial muscles - Deep facial vein - Receives tributaries from deep face; connects facial vein with pterygoid plexus - Pterygoid plexus - Network of vascular channels in masticator space between temporalis/lateral pterygoid muscles - Connects CS, clival venous plexus with face/orbit tributaries - Drains into maxillary vein - Retromandibular vein - Formed from union of maxillary, superficial temporal veins - Lies within parotid space - Passes between external carotid artery (ECA) and CNVII to empty into external jugular vein
    • Neck veins - External jugular vein - From retromandibular, posterior auricular veins - Receives tributaries from scalp, ear, face - Size, extent highly variable - IJV - Caudal continuation of sigmoid sinus - Jugular bulb = dilatation at origin - Courses inferiorly in carotid space posterolateral to ICA, CCA - Unites with subclavian vein to form brachiocephalic vein - Size highly variable; significant side-to-side asymmetry common - Vertebral venous plexus - Suboccipital venous plexus - Tributaries from basilar (clival) plexus, cervical musculature - Interconnects with sigmoid sinuses, cervical epidural venous plexus - Terminates in brachiocephalic vein

IMAGING ANATOMY

  • Overview

    • Extracranial veins highly variable, inconstantly visualized on DSA/CTA/MRA - Scalp, emissary veins - Rarely opacified on normal DSA but often seen on fat-saturated T1 C+ MRs - May become prominent if dural arteriovenous fistula, dural sinus occlusion, sinus pericranii present - Orbital veins - Flow in SOV is normally from extra- to intracranial - Rarely prominent at DSA unless vascular malformation (e.g., C-C fistula) or CS occlusion present (flow reverses) - Face, neck veins - Inconstantly visualized - Pterygoid plexus often prominent on both DSA, T1 C+ MR scans

  • Variations, Anomalies

    • Extracranial venous drainage highly variable
    • Sinus pericranii - Abnormal communication between dural venous sinus, extracranial veins - Seen as vascular scalp mass that communicates with dural sinus via transcalvarial vein (through well-defined bone defect) - Association with intracranial developmental venous anomaly common (± venous varix)

ANATOMY IMAGING ISSUES

  • Imaging Pitfalls

    • Diploic veins, venous "lakes" ("lacunae") may form sharply marginated, well-corticated skull lucencies (do not mistake for metastases or myeloma)
    • Prominent, persistent SOV opacification on DSA is nearly always abnormal but normal on CECT, enhanced MR
    • Asymmetric IJVs are common; 1 IJV may be many times size of contralateral IJV
    • Extracranial venous plexuses (pterygoid, suboccipital) can normally be very prominent

36de7498-fddf-4026-ad3a-bb2179194894

Images

Graphic

Anteroposterior view of the extracranial venous system depicts the major neck veins, their drainage into the mediastinum, and their numerous interconnections with the intracranial venous system. The pterygoid venous plexus receives tributaries from the cavernous sinus and provides an important potential source of collateral venous drainage if the transverse or sigmoid sinuses become occluded. Anteroposterior view of the extracranial venous system depicts the major neck veins, their drainage into the mediastinum, and their numerous interconnections with the intracranial venous system. The pterygoid venous plexus receives tributaries from the cavernous sinus and provides an important potential source of collateral venous drainage if the transverse or sigmoid sinuses become occluded.

Anteroposterior view of the extracranial venous system depicts the major neck veins, their drainage into the mediastinum, and their numerous interconnections with the intracranial venous system. The pterygoid venous plexus receives tributaries from the cavernous sinus and provides an important potential source of collateral venous drainage if the transverse or sigmoid sinuses become occluded. Anteroposterior view of the extracranial venous system depicts the major neck veins, their drainage into the mediastinum, and their numerous interconnections with the intracranial venous system. The pterygoid venous plexus receives tributaries from the cavernous sinus and provides an important potential source of collateral venous drainage if the transverse or sigmoid sinuses become occluded.

Sagittal graphic depicts the major extracranial veins of the scalp, face, and neck. Significant tributaries are also shown. Numerous anastomoses between the intra- and extracranial veins provide a potential collateral pathway for venous drainage if a major dural sinus becomes thrombosed. Note collateral drainage from the cavernous sinus anteriorly (through the superior and inferior ophthalmic veins to the facial vein) as well as inferiorly (through basilar foramina to the pterygoid venous plexus) and posteriorly (through the superior and inferior petrosal sinuses). The internal and external jugular veins also have significant interconnections. The deep vertebral venous plexus with its intra- and extraspinal anastomoses is not shown in this graphic. Sagittal graphic depicts the major extracranial veins of the scalp, face, and neck. Significant tributaries are also shown. Numerous anastomoses between the intra- and extracranial veins provide a potential collateral pathway for venous drainage if a major dural sinus becomes thrombosed. Note collateral drainage from the cavernous sinus anteriorly (through the superior and inferior ophthalmic veins to the facial vein) as well as inferiorly (through basilar foramina to the pterygoid venous plexus) and posteriorly (through the superior and inferior petrosal sinuses). The internal and external jugular veins also have significant interconnections. The deep vertebral venous plexus with its intra- and extraspinal anastomoses is not shown in this graphic.

Sagittal CECT

Series of 2 reconstructed sagittal views from a thin-section axial CECT scan shows the internal jugular vein (IJV) and its relationship to the skull base. Note the proximity of the IJV and jugular bulb to the petrous temporal bone and internal carotid artery (ICA). The IJV descends inferiorly within the carotid space. Series of 2 reconstructed sagittal views from a thin-section axial CECT scan shows the internal jugular vein (IJV) and its relationship to the skull base. Note the proximity of the IJV and jugular bulb to the petrous temporal bone and internal carotid artery (ICA). The IJV descends inferiorly within the carotid space.

IJVs vary significantly in size. Significant side-to-side asymmetry is common. This IJV is average in size and configuration. IJVs vary significantly in size. Significant side-to-side asymmetry is common. This IJV is average in size and configuration.

Coronal CECT

A series of 2 coronal views from a thin-section CECT scan of the neck show the IJVs and some tributaries that arise near the skull base. This view shows significant side-to-side asymmetry of the 2 IJVs, a common normal variant. A series of 2 coronal views from a thin-section CECT scan of the neck show the IJVs and some tributaries that arise near the skull base. This view shows significant side-to-side asymmetry of the 2 IJVs, a common normal variant.

Extensive interconnections between the intra- and extracranial venous systems are normally present. The hypoglossal venous plexus, petrosal sinuses, clival venous plexus, cavernous sinus, and pterygoid plexus are extensively interconnected. Extensive interconnections between the intra- and extracranial venous systems are normally present. The hypoglossal venous plexus, petrosal sinuses, clival venous plexus, cavernous sinus, and pterygoid plexus are extensively interconnected.

3T Axial T1 C+ MR

A series of 6 axial T1 C+ MR scans are shown from inferior to superior. The upper cervical epidural venous plexus is seen on this section. Vessels within the carotid space are well delineated. The cervical ICA lies anteromedial to the IJV in this space. A series of 6 axial T1 C+ MR scans are shown from inferior to superior. The upper cervical epidural venous plexus is seen on this section. Vessels within the carotid space are well delineated. The cervical ICA lies anteromedial to the IJV in this space.

Section through the foramen magnum shows the interconnections between the lower clival, upper cervical epidural, and suboccipital venous plexi. Condylar emissary veins also connect the intra- and extracranial veins around the foramen magnum and upper cervical spinal canal. Section through the foramen magnum shows the interconnections between the lower clival, upper cervical epidural, and suboccipital venous plexi. Condylar emissary veins also connect the intra- and extracranial veins around the foramen magnum and upper cervical spinal canal.

A more inferior section through the upper part of the extracranial IJVs shows the inhomogeneous signal caused by spin dephasing. Unusually large condylar emissary veins are present, connecting with the suboccipital veins. A more inferior section through the upper part of the extracranial IJVs shows the inhomogeneous signal caused by spin dephasing. Unusually large condylar emissary veins are present, connecting with the suboccipital veins.

Scans continue superiorly. Section through the medulla, just above the foramen magnum, shows the hypoglossal venous plexus and its interconnections with the clival venous plexus and large condylar emissary veins. Note asymmetry of the jugular bulbs at this level, a common normal variant. Scans continue superiorly. Section through the medulla, just above the foramen magnum, shows the hypoglossal venous plexus and its interconnections with the clival venous plexus and large condylar emissary veins. Note asymmetry of the jugular bulbs at this level, a common normal variant.

Section through the inferior clivus at the level of the hypoglossal canals shows prominent venous plexi traversing the hypoglossal canals. Note interconnections between the clival venous plexus and extracranial IJV via the hypoglossal venous plexi. Section through the inferior clivus at the level of the hypoglossal canals shows prominent venous plexi traversing the hypoglossal canals. Note interconnections between the clival venous plexus and extracranial IJV via the hypoglossal venous plexi.

This scan shows the jugular bulbs nicely. This scan shows the jugular bulbs nicely.

3T Coronal T1 C+ MR

A series of 6 coronal fat-saturated T1 C+ MR scans from posterior to anterior demonstrate the numerous anastomoses between the posterior fossa dural venous sinuses and the extensive venous plexi that surround the upper cervical spine. These interconnections may provide a source for collateral venous drainage if the jugular vein becomes occluded. A series of 6 coronal fat-saturated T1 C+ MR scans from posterior to anterior demonstrate the numerous anastomoses between the posterior fossa dural venous sinuses and the extensive venous plexi that surround the upper cervical spine. These interconnections may provide a source for collateral venous drainage if the jugular vein becomes occluded.

Section through the cervicomedullary junction demonstrates prominent veins in and around the spine and posterior skull base. Section through the cervicomedullary junction demonstrates prominent veins in and around the spine and posterior skull base.

Section through the middle of the upper cervical spine and foramen magnum nicely demonstrates the numerous interconnections between prominent suboccipital veins, vertebral venous plexus, and epidural venous plexus. Section through the middle of the upper cervical spine and foramen magnum nicely demonstrates the numerous interconnections between prominent suboccipital veins, vertebral venous plexus, and epidural venous plexus.

This section is more anteriorly directly through the jugular foramen. Note intensely enhancing IJV seen superolateral to the occipital condyles. The jugular tubercles and occipital condyles together resemble the outline of 2 eagles. The head of the eagle (jugular tubercle) separates the internal jugular bulb and vein from the hypoglossal canal and its venous plexus, nicely seen here. This section is more anteriorly directly through the jugular foramen. Note intensely enhancing IJV seen superolateral to the occipital condyles. The jugular tubercles and occipital condyles together resemble the outline of 2 eagles. The head of the eagle (jugular tubercle) separates the internal jugular bulb and vein from the hypoglossal canal and its venous plexus, nicely seen here.

Scan just anterior to the IJVs shows the ICA running cephalad within the carotid space. The ICA lies anteromedial to the IJV. Scan just anterior to the IJVs shows the ICA running cephalad within the carotid space. The ICA lies anteromedial to the IJV.

Scan through the mandibular condyles and lower clivus shows prominent enhancing veins under the skull base within the pterygoid muscles. These constitute the pterygoid venous plexus, which is usually opacified on T1 C+ MR scans of the neck. Scan through the mandibular condyles and lower clivus shows prominent enhancing veins under the skull base within the pterygoid muscles. These constitute the pterygoid venous plexus, which is usually opacified on T1 C+ MR scans of the neck.

Graphic & Axial CECT

Graphic and accompanying axial CECT scans depict the venous structures within the midneck. The IJV lies posterolateral to the carotid artery within the carotid space. Graphic and accompanying axial CECT scans depict the venous structures within the midneck. The IJV lies posterolateral to the carotid artery within the carotid space.

Axial CECT depicts the neck vessels at the C1 level. Axial CECT depicts the neck vessels at the C1 level.

This image depicts the neck vessels at the level of the hyoid bone. This image depicts the neck vessels at the level of the hyoid bone.

Reference in New Issue View Git Blame Copy Permalink