Findings of a right upper lobe collapse (atelectasis) typically present characteristic signs due to the volume loss in the affected lobe and the secondary changes in surrounding structures. Some of the common findings include:
Volume Loss and Collapse of the Right Upper Lobe:
The right upper lobe appears shrunken or collapsed.
The collapsed lobe may present as a triangular or wedge-shaped opacity, particularly visible on cross-sectional imaging.
The interlobar fissure (minor and major) may be displaced toward the right upper lobe due to volume loss.
Elevation of the Right Horizontal Fissure:
The minor (horizontal) fissure is typically displaced upward due to the loss of volume in the right upper lobe.
The major fissure may also move superiorly to fill the space left by the collapsed lobe.
Mediastinal Shift:
There may be a shift of the mediastinum (heart, trachea, and great vessels) toward the right (the side of the collapse) as the lung volume decreases, especially in more severe cases.
Crowding of Bronchovascular Structures:
The bronchi and vessels within the right upper lobe may appear crowded or distorted due to the collapse.
Hilum Shift:
The right hilum, where the bronchi and vessels enter the lung, may also shift superiorly as the upper lobe contracts.
Compensatory Hyperinflation of Adjacent Lobes:
The right middle and lower lobes may appear hyperinflated or overexpanded to compensate for the lost volume of the collapsed upper lobe.
Golden S Sign (in cases of obstructing mass):
In some cases where the collapse is due to a central mass (such as a tumor), the Golden S sign may be seen. This sign refers to an S-shaped curvature of the minor fissure caused by the mass pushing the fissure upward, while the collapsed lobe pulls it inward.
Opacity in the Affected Lobe:
The collapsed upper lobe may appear as a dense opacity on imaging, typically located in the upper portion of the right lung.
Air Bronchograms:
If the collapse is non-obstructive, air bronchograms (air-filled bronchi seen within the collapsed, opaque lung) may be visible, helping to differentiate the collapse from other conditions like consolidation.
Associated Pleural Changes:
Chronic collapse may be associated with pleural thickening or even mild pleural effusion.