Topics

Topic

design image
Deep brachial artery

The deep brachial artery (also known as the profunda brachii artery) is the largest and most significant branch of the brachial artery. It arises high in the arm and travels posteriorly with the radial nerve through the radial (spiral) groove of the humerus. It is the primary arterial supply to the triceps brachii muscle and plays an essential role in collateral circulation around the elbow.

Its deep location, intimate relationship with the radial nerve, and involvement in elbow collateral networks make it important in traumatic and vascular evaluation of the upper arm.

Synonyms

  • Profunda brachii artery

  • Deep artery of the arm

  • Arm profunda

Origin, Course, and Termination

Origin:

  • Arises from the posterior aspect of the brachial artery, typically 1–3 cm distal to the teres major tendon.

Course:

  • Passes posteriorly between the long and medial heads of the triceps brachii.

  • Enters the radial (spiral) groove with the radial nerve on the posterior humerus.

  • Travels obliquely inferolaterally, remaining deep to the triceps.

Termination:

  • Ends near the distal humerus by dividing into:

    • Radial collateral artery

    • Middle collateral artery
      These branches participate in the elbow collateral arterial network.

Relations

  • Superiorly: Brachial artery, teres major

  • Posteriorly: Triceps brachii (long, lateral, and medial heads)

  • Anteriorly: Posterior humeral shaft in spiral groove

  • Laterally: Radial nerve closely accompanying the artery

  • Inferiorly: Lateral intermuscular septum, radial collateral artery pathway

Branches

  • Muscular branches to triceps brachii

  • Nutrient branches to humerus

  • Terminal branches: radial collateral and middle collateral arteries

Function

  • Primary arterial supply to posterior arm compartment

  • Contributes to collateral circulation around elbow joint

  • Ensures perfusion even during elbow flexion, which may compress the main brachial artery

Clinical Significance

  • Radial nerve injury: Due to close association in the spiral groove, fractures may damage both

  • Humeral shaft fractures: Risk lacerating or compressing the artery

  • Collateral importance: Crucial during brachial artery occlusion or trauma

  • Surgical relevance: Must be preserved in posterior arm approaches and triceps-sparing exposures

MRI Appearance

T1-weighted images:

  • Artery displays a low-signal (dark) flow void due to fast-moving blood

  • Surrounding fat: bright, providing clear vessel contrast

  • Vessel wall: thin low-signal rim

  • Muscle of triceps: intermediate signal

T2-weighted images:

  • Lumen appears as a dark flow void

  • Vessel wall remains low signal

  • Triceps muscle: intermediate-to-low signal, slightly darker than on T1

  • Fat planes surrounding artery appear bright

STIR:

  • Artery: dark flow void

  • Triceps muscle: intermediate-to-dark signal

  • Fat is fully suppressed, creating higher contrast between artery and soft tissues

T1 Fat-Saturated Post-Contrast:

  • Normal artery: intense, smooth, homogeneous enhancement of lumen

  • Vessel wall appears as a thin, enhancing outline

  • Muscle enhances mildly and uniformly

CT Appearance

Non-Contrast CT:

  • Artery visualized as a round or tubular soft-tissue density structure adjacent to the humerus

  • Surrounding muscles appear as soft-tissue density; fat planes clearly outline the vessel

  • May show calcifications if atherosclerotic (rare in this artery)

  • Useful for identifying humeral fractures that may affect the artery

Post-Contrast CT:

  • Artery enhances brightly and homogeneously in arterial phase

  • Course along spiral groove clearly demonstrated

  • Allows delineation from radial nerve, which does not enhance

  • Excellent for identifying luminal narrowing, trauma-related displacement, or extravasation

MRI image

Deep brachial artery