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Right superior lobar bronchus

The right superior lobar bronchus (also known as the eparterial bronchus) is the first major branch of the right main bronchus. It arises above the level of the right pulmonary artery, hence the term “eparterial.” This bronchus supplies the right upper lobe of the lung, dividing into three segmental bronchi: apical (B1), posterior (B2), and anterior (B3).

Anatomically, it courses laterally and slightly upward into the right upper lobe after branching from the right main bronchus. Its relationship superior to the right pulmonary artery is a distinctive anatomical feature, contrasting with all other lobar bronchi, which are hyparterial (arising below their respective pulmonary arteries).

Clinically, it is a key landmark in bronchoscopy, pulmonary resections, segmentectomy, and lung cancer staging, as well as in CT imaging for airway assessment.

Synonyms

  • Eparterial bronchus

  • Right upper lobar bronchus

  • Bronchus of right upper lobe

Function

  • Conducts inspired air into the right upper lobe of the lung

  • Divides into three segmental bronchi (B1–B3) supplying the apical, posterior, and anterior segments

  • Provides an anatomical landmark for bronchoscopy, thoracic surgery, and radiology

  • Plays a vital role in ventilation of upper lobe parenchyma

Branches

  • Apical segmental bronchus (B1) – supplies apical segment of right upper lobe

  • Posterior segmental bronchus (B2) – supplies posterior segment

  • Anterior segmental bronchus (B3) – supplies anterior segment

MRI Appearance

T1-weighted images:

  • Air-filled lumen appears as a signal void (black)

  • Bronchial wall appears hypointense relative to surrounding lung parenchyma

T2-weighted images:

  • Lumen remains a signal void

  • Fluid or mucus within the bronchus appears bright (hyperintense)

  • Wall thickening (e.g., in bronchitis) can be seen as intermediate-to-high signal

T2 TRUFISP (cardiac/respiratory-gated):

  • Provides bright, high-contrast images of airway–parenchymal interfaces

  • Demonstrates dynamic motion of the bronchus with respiration

  • Useful in functional airway imaging and evaluation of obstruction

STIR:

  • Fat suppression enhances visibility of peribronchial edema or inflammatory changes

  • Pathological involvement (infection, tumor infiltration) appears hyperintense

T1 Post-Contrast (Gadolinium-enhanced MRI):

  • Bronchial wall may enhance if inflamed or neoplastic

  • Enhances delineation of peribronchial tumors and lymph nodes

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

  • Provides high-resolution 3D airway maps

  • Demonstrates the origin of the right superior lobar bronchus above the pulmonary artery

  • Useful for preoperative planning in lung resections and congenital anomaly assessment

CT Appearance

CT (Standard or High-Resolution CT):

  • Right superior lobar bronchus clearly seen branching above the right pulmonary artery

  • Lumen appears as an air-filled (hypodense) structure with thin walls

  • HRCT demonstrates wall thickening, stenosis, or obstruction

CT Coronary Angiography / CT Bronchography (CCTA protocols with venous phase):

  • Demonstrates the relationship of the right superior lobar bronchus to pulmonary arteries and veins

  • Multiplanar and 3D reconstructions allow precise mapping for bronchoscopy, segmentectomy, and tumor localization

  • Detects endobronchial lesions, peribronchial tumors, compression by lymphadenopathy, and congenital anomalies

CT image

Right superior lobar bronchus anatomy CT coronal image -img-00000-00000

MRI image

Right superior lobar bronchus anatomy MRI coronal image -img-00000-00000