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Anterior basal segmental artery of right lung

The anterior basal segmental artery (A7) is a branch of the right lower lobe pulmonary artery, supplying the anterior basal segment (S7) of the right lower lobe. It originates from the basal trunk of the right pulmonary artery, typically alongside the medial (A7+8), lateral (A9), and posterior basal (A10) arteries.

The anterior basal segment lies in the anteroinferior portion of the right lower lobe, adjacent to the diaphragm and costal pleura. The A7 artery courses forward and downward into this segment, accompanying the anterior basal bronchus (B7) and its corresponding pulmonary vein branch.

Clinically, precise knowledge of the anterior basal segmental artery is critical in segmentectomy, lobectomy, lung transplantation, and pulmonary embolism imaging, as well as in differentiating arterial variants during interventional procedures.

Synonyms

  • A7 artery

  • Right anterior basal pulmonary artery

  • Arteria segmenti basalis anterioris pulmonis dextri

Function

  • Supplies oxygen-depleted blood to the anterior basal segment (S7) of the right lower lobe for gas exchange

  • Contributes to perfusion of the anteroinferior right lung adjacent to the diaphragm

  • Plays a role in surgical lung segmental resections and in embolism distribution in pulmonary vascular disease

Branches

  • Segmental branches that follow the anterior basal bronchus (B7)

  • Terminal branches form capillary networks around alveoli in the anterior basal segment

MRI Appearance

T1-weighted images:

  • A7 artery appears as a signal void (black lumen) due to flowing blood

  • Vessel wall is hypointense, surrounded by intermediate signal lung parenchyma

T2-weighted images:

  • Flow void persists, making the artery a dark tubular structure within the lung hilum

  • Adjacent pathology (edema, tumor, consolidation) appears hyperintense, outlining vessel course

T2 TRUFISP (cardiac/respiratory-gated):

  • Depicts the artery as a bright, well-defined vascular lumen

  • Provides dynamic imaging of pulmonary arterial flow in the lower lobe

  • Useful for evaluating patency, stenosis, or thrombus in the segmental artery

STIR (Short Tau Inversion Recovery):

  • Fat suppression enhances contrast with mediastinal and hilar fat

  • Abnormalities such as perivascular edema or inflammation appear hyperintense

T1 Post-Contrast (Gadolinium-enhanced MRI):

  • A7 artery enhances brightly and homogeneously

  • Filling defects represent embolus, thrombus, or intraluminal tumor

  • Useful for MR pulmonary angiography (MRPA) of segmental branches

MRI Non-Contrast 3D Cardiac/Respiratory-Gated Imaging:

  • Provides a 3D reconstruction of pulmonary arterial branches without contrast

  • Clearly shows the origin, course, and distribution of the A7 artery

  • Useful in patients with renal dysfunction or contrast contraindications

CT Appearance

CT Pulmonary Angiography (CTPA):

  • Gold standard for evaluating pulmonary arteries

  • A7 artery seen as a contrast-opacified tubular branch coursing into the anterior basal segment of the right lower lobe

  • Filling defects indicate pulmonary embolism

  • Thin-slice and multiplanar reconstructions allow precise mapping for segmentectomy or lobectomy planning

  • Differentiates arterial variants and relationships with bronchus and vein

CT images

Anterior basal segmental artery of right lung anatomy CT axial image -img-00000-00000

CT images

Anterior basal segmental artery of right lung anatomy CT axial image -img-00000-00000_00001

MRI images

Anterior basal segmental artery of right lung mri image