Topics

Topic

design image
Superior lobe of left lung

The superior lobe of the left lung is the uppermost lobe of the left lung, occupying the anterosuperior portion of the left hemithorax. It plays a major role in gas exchange and contains distinct bronchopulmonary segments. Owing to its anatomical position, it is closely related to the heart, mediastinum, and major thoracic vessels.

It is an essential region evaluated in thoracic imaging, pulmonary anatomy, and clinical assessment of respiratory disease.

Synonyms

  • Left upper lobe

  • Superior lobe of left lung

Location

  • Located in the upper part of the left hemithorax

  • Extends from the lung apex to the oblique fissure

  • Anterior and superior to the inferior lobe of the left lung

  • Lateral to the mediastinum

  • Posterior to the anterior chest wall

  • Overlies the heart and great vessels medially

Anatomical components

  • Bronchopulmonary segments:

    • Apicoposterior segment

    • Anterior segment

    • Superior lingular segment

    • Inferior lingular segment

  • Bronchial supply:

    • Left upper lobe bronchus (branch of the left main bronchus)

  • Vascular supply:

    • Branches of the left pulmonary artery

    • Pulmonary veins draining to the left atrium

Relations

Superiorly:

  • Thoracic inlet

  • First rib and clavicle

Inferiorly:

  • Oblique fissure

  • Inferior lobe of the left lung

Medially:

  • Heart (left ventricle and left atrium)

  • Aortic arch

  • Left pulmonary artery

Laterally:

  • Ribs and intercostal muscles

Anteriorly:

  • Anterior chest wall

Posteriorly:

  • Upper thoracic vertebrae

X-ray appearance

Chest radiograph (PA view):

  • Occupies the upper and mid zones of the left lung

  • Forms the left apical lung shadow

  • Anteriorly located, contributing to the left cardiac border via the lingula

  • Separated from the inferior lobe by the oblique fissure (usually not directly visible)

Lateral view:

  • Seen predominantly in the anterior upper lung field

  • Lies anterior to the oblique fissure

CT appearance (lung window)

Lung window settings:

  • Parenchyma: Normal aerated lung with low attenuation and fine vascular markings

  • Bronchi: Thin-walled air-filled bronchi extending to the periphery

  • Fissure: Oblique fissure seen as a thin curvilinear line separating superior and inferior lobes

  • Lingula: Identified anteriorly, analogous to the right middle lobe

MRI appearance

T1-weighted images:

  • Lung parenchyma: Low signal intensity due to air content

  • Pulmonary vessels: Intermediate signal within the low-signal lung background

  • Chest wall and mediastinal fat: High signal

T2-weighted images:

  • Lung parenchyma: Low signal intensity

  • Pulmonary vessels and bronchi walls: Intermediate signal

  • Pleural surfaces: Thin low-signal interface

STIR:

  • Lung parenchyma: Very low signal

  • Chest wall and pleura: Suppressed fat signal with improved contrast

CT image

X-Ray image

Superior lobe of left lung X RAY anatomy image -img-00000-00000