Topics

Topic

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Right lung

The right lung is the larger of the two lungs and occupies the right pleural cavity. It is shorter and wider than the left lung due to the high position of the liver and absence of a cardiac notch. The right lung contains three lobes—upper, middle, and lower—separated by the horizontal fissure and oblique fissure.

Its hilum contains the right main bronchus, pulmonary arteries and veins, bronchial arteries, lymphatics, and nerves. The right lung is essential for gas exchange, ventilation, and maintaining respiratory mechanics through its lobar and segmental architecture.

Synonyms

  • Pulmo dexter

  • Right pulmonary organ

Location and Structure

  • Occupies the right thoracic cavity, extending from the thoracic inlet to the diaphragm.

  • Subdivided into three lobes:

    • Upper lobe

    • Middle lobe

    • Lower lobe

  • Contained within the visceral pleura; surrounded by parietal pleura.

  • Right lung has 10 bronchopulmonary segments.

  • Hilum located medially, connecting lung to mediastinum.

Relations

  • Superiorly: Cervical pleura and first rib

  • Inferiorly: Diaphragm and right lobe of liver

  • Anteriorly: Right costal cartilages and sternum

  • Posteriorly: Thoracic vertebrae and paravertebral musculature

  • Medially: Mediastinum, right atrium, superior vena cava, azygos vein, esophagus

  • Laterally: Costal pleura and thoracic wall

  • Inferomedially: Pulmonary ligament

Lobes and Fissures

  • Right Upper Lobe: Apex, posterior and anterior segments

  • Right Middle Lobe: Medial and lateral segments

  • Right Lower Lobe: Superior, medial basal, lateral basal, anterior basal, and posterior basal segments

  • Fissures:

    • Horizontal fissure: Separates upper and middle lobes

    • Oblique fissure: Separates upper/middle lobes from lower lobe

Hilum

  • Bronchus: Right main bronchus (short, wide, more vertical than left)

  • Pulmonary artery: Anterior to bronchus

  • Pulmonary veins: Inferior and anterior

  • Bronchial arteries and lymphatics: Surround bronchial tree

Function

  • Gas exchange through alveoli

  • Ventilation of three lobes and ten segments

  • Contributes to acid–base regulation

  • Plays a role in immune filtration through pulmonary macrophages

  • Elastic recoil supports passive exhalation

Clinical Significance (Anatomy Only – No Imaging Pathology)

  • Right main bronchus is more vertical → easier pathway for foreign body aspiration

  • Right lung volume greater than left due to no cardiac notch

  • Important in segmental lung resections and bronchoscopic navigation

  • Hilum and fissure anatomy crucial in thoracic surgery and pulmonary embolism mapping

MRI Appearance

T1-weighted images:

  • Lung parenchyma: Very low signal (dark) due to low proton density

  • Blood vessels: Flow voids or low-signal tubular structures

  • Pleura: Thin low-signal line

  • Mediastinal fat and chest wall fat: Bright

  • Bronchial tree: Low signal with air-filled lumen

T2-weighted images:

  • Normal lung parenchyma: Very low signal (dark)

  • Vessels: Tubular low-signal structures

  • Pleura: Thin low-signal margin

  • Airway lumen: Very low signal

  • Adjacent soft tissues (heart, mediastinum): Intermediate-to-bright

STIR:

  • Lung parenchyma: Very low to low signal

  • Pleura: Low signal

  • Vessels: Remain low signal

  • Surrounding fat: Suppressed (dark)

  • Chest wall muscles: Intermediate signal

T1 Fat-Saturated Post-Contrast:

  • Pulmonary vessels: Homogeneous bright enhancement

  • Mediastinal fat: Suppressed

  • Pleura: May show slight thin enhancement

  • Lung parenchyma: Remains low signal

  • Bronchial walls: Thin, low-signal rings

CT Appearance

Non-Contrast CT:

  • Lung parenchyma: Very low attenuation due to air (approx. –900 HU)

  • Bronchi: Air-filled low-density lumens with thin high-density walls

  • Pulmonary vessels: Intermediate attenuation

  • Pleura: Thin high-attenuation line

  • Fissures: Thin, sharply defined linear structures

  • Hilum: Clearly visualized bronchi and vessels

Post-Contrast CT:

  • Pulmonary arteries and veins: Enhance brightly

  • Bronchi: Non-enhancing air-filled structures

  • Parenchyma: Maintains low attenuation

  • Mediastinum and chest wall structures: Enhanced visualization

  • Fissures: Clear interfaces between lobes

MRI image

Right lung mri coronal image

CT image

Right lung ct axial image