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Superior lobar artery left lung

The superior lobar artery of the left lung, also known as the left upper lobe artery, is the main pulmonary arterial branch supplying the superior lobe of the left lung (segments S1–S5). It arises from the left pulmonary artery as it courses laterally from the pulmonary trunk and then divides into segmental branches.

Typically, the superior lobar artery gives rise to the apicoposterior artery (S1+S2), anterior artery (S3), superior lingular artery (S4), and inferior lingular artery (S5). Its segmental branching accompanies bronchi and veins, forming part of the bronchovascular bundle within each pulmonary segment.

The artery is clinically significant in pulmonary embolism, lung cancer resections, and segmentectomy planning, as well as in CT and MRI pulmonary vascular mapping. Variations are common, and detailed preoperative imaging is essential.

Synonyms

  • Left upper lobar artery

  • Superior branch of left pulmonary artery

  • Left pulmonary artery superior division

Function

  • Supplies oxygen-poor blood to the left upper lobe for oxygenation in alveoli

  • Contributes to gas exchange via its segmental branches S1–S5

  • Serves as a key landmark in thoracic surgery (lobectomy/segmentectomy) and interventional procedures

Branches

  • Apicoposterior artery (S1+S2)

  • Anterior artery (S3)

  • Superior lingular artery (S4)

  • Inferior lingular artery (S5)

MRI Appearance

T1-weighted images:

  • Lumen appears as a signal void (black) due to arterial flow

  • Wall hypointense, adjacent mediastinal fat enhances visualization

T2-weighted images:

  • Arterial lumen remains a signal void

  • Perivascular pathology (e.g., edema, tumor encasement) may appear hyperintense

T2 TRUFISP (cardiac/respiratory-gated):

  • Depicts superior lobar artery as a bright, continuous vascular lumen with clear branching into segmental arteries

  • Cine-like visualization allows assessment of arterial patency and branching

STIR (Short Tau Inversion Recovery):

  • Suppresses fat, improving visualization against surrounding lung tissue

  • Highlights perivascular edema or inflammation as hyperintense regions

T1 Post-Contrast (Gadolinium-enhanced MRI):

  • Artery enhances brightly and homogeneously

  • Useful for evaluating stenosis, emboli, or vascular invasion by tumor

MRI Non-Contrast 3D Cardiac-Gated Imaging (Whole-heart / Pulmonary MRA):

  • Provides 3D mapping of superior lobar artery and its segmental branches

  • Useful in congenital anomaly detection, surgical planning, and embolism assessment without contrast

CT Appearance

CT Pulmonary Angiography (CTPA):

  • Gold standard for non-invasive evaluation

  • Clearly shows the origin from the left pulmonary artery, segmental branching (S1–S5), and distal arborization

  • Detects pulmonary embolism, stenosis, extrinsic compression, or tumor encasement

  • Multiplanar and 3D reconstructions guide lobectomy/segmentectomy planning and interventional radiology

CT image

Superior lobar artery of left lung anatomy CT axial image -img-00000-00000

MRI image

Superior lobar artery of left lung mri image