Right upper lobe atelectasis

(A) Contrast-enhanced axial computed tomography (CT) thorax in a patient with bronchogenic carcinoma shows the atelectatic right upper lobe in the paramediastinal location with vertical position of the right minor fissure. Marked enlargement of the tracheobronchial lymph nodes is also seen (dashed arrow) with compression of the superior vena cava (arrow) and compensatory dilation of the azygos vein (arrowhead).
(B) Axial CT thorax shows the paramediastinal location of the atelectatic right upper lobe, mediastinal shift to the right, and hyperexpansion of the right middle lobe outlining the lateral border of the atelectatic right upper lobe.
(C) Coronal multiplanar reformat in the same patient shows the atelectatic right upper lobe and the occluded right upper lobe bronchus (short arrow).