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Topic

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Brachiocephalic trunk

The brachiocephalic trunk is a major artery that arises from the aortic arch and supplies blood to the right arm and the right side of the head and neck. It is the first and largest branch of the aortic arch, dividing into the right subclavian artery and the right common carotid artery. Its identification and evaluation are crucial in both anatomical studies and clinical imaging, especially in the assessment of vascular diseases and pre-surgical planning.

Synonyms

  • Innominate artery

  • Brachiocephalic artery

  • Arteria brachiocephalica (Latin)

Function

  • Supplies oxygenated blood to the right side of the head and neck via the right common carotid artery

  • Supplies the right upper limb via the right subclavian artery

  • Acts as a conduit between the aortic arch and its two major branches

MRI Appearance

  • T1-weighted Images:

    • The brachiocephalic trunk appears as a flow void (dark signal) due to rapid blood flow.

    • The vessel wall may be visualized if pathology (e.g., thrombus, wall thickening) is present.

  • T2-weighted Images:

    • Also shows as a flow void (dark structure).

    • Signal changes may be present in case of slow flow or intraluminal pathology.

  • STIR (Short Tau Inversion Recovery):

    • Suppresses fat, but the brachiocephalic trunk remains as a flow void.

    • Useful for detecting vessel wall edema or inflammatory changes.

  • TOF (Time-of-Flight) MR Angiography:

    • The brachiocephalic trunk appears hyperintense (bright) due to inflow of unsaturated blood protons.

    • Excellent for assessing patency, stenosis, or aneurysms.

CT Appearance

  • Non-contrast CT:

    • The brachiocephalic trunk is visualized as a tubular, soft-tissue density structure in the superior mediastinum.

    • Not well differentiated from adjacent vessels without contrast.

  • CTA (CT Angiography):

    • The brachiocephalic trunk is clearly visualized as a contrast-filled, high-attenuation vessel arising from the aortic arch.

    • Enables detailed assessment of vessel lumen, wall irregularities, stenosis, aneurysm, or dissection.

    • Allows for multiplanar and 3D reconstructions for surgical or interventional planning.

MRI images

Brachiocephalic trunk MRI coronal t2 image

CT image

Brachiocephalic trunk CT IMAGE