Acute lung diseases generally refers to pneumonia (chest infection) which causes symptoms of cough with sputum, fever, and shortness of breath. It generally requires antibiotics to help it clear up but its location and extent is easily visible on a CT scan.
Other acute lung diseases include clots on the lung (pulmonary embolus), fluid on the lung (congestive cardiac failure), asthma and collapse of the lung (pneuomothorax), all of which can also be distinguished on CT scanning.