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Thyrocervical trunk

The thyrocervical trunk is a short but clinically significant arterial branch that arises from the first part of the subclavian artery, just lateral to the vertebral artery origin and medial to the phrenic nerve crossing the subclavian artery. It typically measures about 1–2 cm in length before dividing into multiple branches.

It courses superomedially, passing upward and forward in the lower neck, where it rapidly divides into its terminal branches. The thyrocervical trunk supplies an extensive vascular network to the thyroid gland, cervical musculature, esophagus, trachea, larynx, vertebral column, scapular region, and posterior neck tissues.

Its main branches are the inferior thyroid artery, ascending cervical artery, transverse cervical artery, and suprascapular artery. These arteries form anastomotic connections with vessels from the external carotid artery, costocervical trunk, and subscapular artery, making the thyrocervical trunk an important contributor to collateral circulation in the head, neck, and shoulder girdle.

Due to its location, the thyrocervical trunk is important in neck surgeries (e.g., thyroidectomy, cervical lymph node dissection), interventional radiology (embolization of head and neck tumors, control of bleeding), and vascular pathology (aneurysm, dissection, or stenosis). Variations in its branching pattern are common and can affect surgical approaches.

Synonyms

  • Truncus thyrocervicalis

  • Thyrocervical artery trunk

  • Thyrocervical branch of subclavian artery

Function

  • Provides arterial supply to the thyroid gland, cervical vertebrae, esophagus, trachea, larynx, prevertebral muscles, scapular region, and trapezius muscle

  • Plays a role in collateral circulation between the subclavian, carotid, and axillary systems

  • Ensures adequate blood flow during dynamic neck and shoulder movements

  • Supports vascular supply during surgical interventions and recovery in the neck and shoulder

Branches

  • Inferior thyroid artery → supplies the thyroid gland, parathyroid glands, larynx, trachea, and esophagus

  • Ascending cervical artery → supplies prevertebral muscles, cervical spinal cord, and meninges via spinal branches

  • Transverse cervical artery → supplies trapezius and posterior scapular region; may give rise to dorsal scapular artery in some cases

  • Suprascapular artery → supplies supraspinatus, infraspinatus, and scapular anastomosis

MRI Appearance

T1-weighted images:

  • Appears as a flow void (signal loss) due to rapid arterial blood flow

  • Vessel wall appears as a thin hypointense rim within surrounding neck fat

  • Branches are seen in relation to thyroid, cervical muscles, and scapular region

T2-weighted images:

  • Blood flow remains a signal void, but surrounding fat and muscle contrast defines vascular course

  • Useful for identifying vascular displacement by tumors or masses

STIR (Short Tau Inversion Recovery):

  • Fat suppression highlights the vascular path through neck fat planes

  • Pathologies (e.g., aneurysm, dissection, inflammatory change) may appear as hyperintensity of wall or perivascular tissue

T1 Post-Contrast (Gadolinium-enhanced):

  • Thyrocervical trunk and branches show bright homogeneous enhancement

  • Improves detection of vascular malformations, stenosis, aneurysms, or branch anatomy

  • Essential for MR angiography of cervical vessels

CT Appearance

Non-contrast CT:

  • Appears as a small soft tissue density tubular structure near the origin of the subclavian artery

  • Calcifications may be seen in older patients or with vascular disease

CT Angiography (CTA):

  • Clearly demonstrates the origin, length, branching pattern, and variations of the thyrocervical trunk

  • Useful for surgical planning (thyroid, cervical spine, shoulder surgery)

  • Identifies stenosis, aneurysm, dissection, or anomalous branching patterns

  • Provides detailed visualization of anastomoses with external carotid, costocervical, and axillary arteries

MRI image

Thyrocervical trunk anatomy MRI coronal image -img-00000-00000

CT images

Thyrocervical trunk anatomy CT axial image -img-00000-00000

CT images

Thyrocervical trunk anatomy CT coronal image -img-00000-00000

MRI image

Thyrocervical trunk anatomy MRI axial image -img-00000-00000