18 Lobar or Segmental Collapse*

CLINICAL IMAGAGINGAN ATLAS OF DIFFERENTIAL DAIGNOSIS

EISENBERG

DR. Muhammad Bin Zulfiqar PGR-FCPS III SIMS/SHL

• Fig C 18-1 Bronchogenic carcinoma. Typical reverse S-shaped curve (Golden's sign) representing collapse of the right upper lobe associated with malignant bronchial obstruction.

• Fig C 18-2 Central bronchial adenoma. (A) Frontal chest radiograph demonstrates a right lower lobe density with obscuration of the right hemidiaphragm and relative preservation of the right border of the heart, consistent with right lower lobe collapse. (B) Tomography shows an ill-defined mass causing a high-grade obstruction of the right lower lobe bronchus (arrow).

• Fig C 18-3 Malpositioned endotracheal tube. Collapse of the left lung, especially the left lower lobe, due to an endotracheal tube (arrows) in the right main-stem bronchus that effectively blocks the passage of air into the left bronchial tree.

• Fig C 18-4 Malpositioned endotracheal tube. Inordinately low position of the endotracheal tube in the bronchus intermedius causes collapse of the right upper lobe and the entire left lung.

• Fig C 18-5 Mucous plug in a paraplegic. (A) Baseline radiograph is within normal limits. Note the calcified granuloma in the left perihilar region (arrow). (B) Complete collapse of the left lung after the lodging of a mucous plug in the left main-stem bronchus. Note the change in position of the calcified granuloma when the left lung collapses (arrow).

• Fig C 18-6 Right upper lobe collapse. (A) Initial chest radiograph demonstrates the collapsed right upper lobe, which appears as a homogeneous soft-tissue mass (arrows) in the right apex along the upper mediastinum. (B) As the collapsed lobe expands, the soft-tissue has disappeared and the minor fissure (arrow) has reappeared.

• Fig C 18-7 Left upper lobe collapse. (A) Frontal chest radiograph demonstrates a generalized increase in the density of the left hemithorax with no obliteration of the aortic knob or proximal descending aorta. The visualized vascular markings reflect lower lobe vessels. (B) A lateral view confirms the anterior position of the collapsed left upper lobe.

• Fig C 18-8 Right middle lobe collapse. (A) Frontal chest radiograph demonstrates minimal obliteration of the lower part of the right border of the heart (arrows). (B) Lateral view demonstrates collapse of the right middle lobe (arrows).

• Fig C 18-9 Right middle lobe and lingular collapse. (A) Frontal chest radiograph demonstrates obliteration of the right and left borders of the heart. (B) Lateral view demonstrates collapse of both the right middle lobe and the lingula (arrows).

• Fig C 18-10 Right lower lobe collapse. (A) Frontal chest radiograph demonstrates a right lower lung density with preservation of the right border of the heart. The right hemidiaphragm is obscured. (B) Lateral view confirms the presence of right lower lobe collapse (due to bronchogenic carcinoma) with posterior displacement of the major fissure (1). The elevated right hemidiaphragm (2) is obliterated posteriorly by the airless right lower lobe, and the anterior third of the left hemidiaphragm (3) is obscured by the bottom of the heart. The overlapping shadows of the back of the heart (4), which lies in the left hemithorax, and the right hemidiaphragm simulate interlobar effusion.35

• Fig C 18-11 Left lower lobe collapse. (A) Frontal chest radiograph demonstrates obliteration of the descending thoracic aorta and obscuration of much of the left hemidiaphragm. (B) Lateral view confirms the posterior portion of the collapsed left lower lobe.