Collapsed lung. Coloured Computed Tomography (CT) scan through a patient's chest showing collapse (atelectasis) of the right lobe of a lung. The rounded bone at lower centre is the spine. Healthy lung tissue is red (at left and at lower right). The upper lobe of the lung on the right has collapsed and is fluid-filled (consolidation; blue/pink area in upper right). Healthy tissue in the right-hand lung has shrunk as a result (lower right, red. The yellow structure in the centre is the arch of the aorta (the main blood vessel from the heart). Lung collapse can be caused by disease or injury and is seldom fatal.