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Occipital veins

The occipital veins are superficial venous structures located in the posterior scalp region. They primarily drain the posterior aspect of the scalp and communicate with intracranial venous sinuses via the occipital emissary veins. These veins play a crucial role in venous drainage of the scalp and may serve as collateral pathways in cases of venous outflow obstruction. Occipital veins have clinical importance in both vascular and neurosurgical contexts, especially regarding emissary vein connections and potential for transmission of infection.

Synonyms:

  • Posterior scalp veins

  • Occipital emissary veins (for the emissary variant)

  • Vena occipitalis (Latin term)

Function:

  • Drain venous blood from the posterior scalp

  • Connect superficial scalp venous system with the intracranial dural venous sinuses (via occipital emissary veins)

  • Serve as collateral channels in cases of jugular vein obstruction

  • Participate in thermoregulation of the scalp

  • Potential routes for spread of infection between scalp and intracranial compartments

MRI Appearance:

  • T1-Weighted Images:

    • Occipital veins appear as tubular, flow void structures (signal void) due to fast-flowing blood

    • When thrombosed, may show intermediate or hyperintense signal

  • T2-Weighted Images:

    • Normally visualized as signal voids (low signal) due to rapid flow

    • Slow flow or thrombosis may appear hyperintense

    • Better seen if there is adjacent pathology or thrombosis

  • Phase Contrast 3D (PC 3D) MRI:

    • Occipital veins are well depicted as flow-sensitive structures

    • Appear as bright/high signal linear or curvilinear channels

    • Useful for visualizing venous flow dynamics and direction

  • Post-Contrast T1-Weighted Images:

    • Enhancing tubular structures representing patent occipital veins

    • Enhancement is more prominent if slow flow or dilated veins are present

    • Thrombosed veins may lack enhancement or appear as filling defects

CT Appearance:

  • Not easily visualized on non-contrast CT unless enlarged or calcified

  • May appear as thin, linear low-density channels in the soft tissues of the posterior scalp

  • Thrombosed veins may be seen as hyperdense tubular structures in acute cases

CT Venography (CTV) Appearance:

  • Clearly visualized as enhancing linear or curvilinear structures in the posterior scalp region

  • Patent occipital veins demonstrate homogeneous contrast opacification

  • CTV can delineate connections with the transverse or sigmoid sinus via emissary foramina

  • Thrombosis or occlusion may present as filling defects or absent visualization

MRI images

Occipital veins MRI 3T axial image

MRI images

Occipital veins MRI 3T coronal image

MRI images

Occipital veins MRI 3T sagittal mip image