CHAPTER 5 The black lung field
5.1 Chronic obstructive pulmonary disease (COPD)
When trying to decide the cause of bilateral black lungs you need to:
Cigarette smoking causes damage to the parenchyma of the lung. Cigarette smoke in a room tends to float upwards, and similarly smoking related lung damage tends to occur in the upper lungs. This image shows how the normal smooth lung texture has been destroyed with the formation of air cysts (bullae – 1) and small black holes in the lung (centrilobular emphysema – 2). The blood vessels through these areas can also become very narrowed, as the body will not perfuse areas of the lung where gas exchange is significantly impaired.
5.2 Pneumothorax
When you see a unilateral black lung you need to:
You must now decide the cause of the blackness. Lung markings are made up of bronchi and blood vessels and it is their absence that makes the lung look black. Vascular shadows will disappear if the lung is replaced by air, which will occur with a pneumothorax or bullous or cystic lung disease or if the vessels are deprived of blood as in a pulmonary embolus. Therefore think pneumothorax, bullae/cyst or pulmonary embolism and: