Pneumonia and tuberculosis can be distinguished on CT, and different types of pneumonia behave differently on lung CT. Large lobar pneumonia tends to layer confined solid shadows, while small lobar pneumonia tends to be multifocal in both lungs. Patients with viral infections tend to have network-like, or ground glass, changes. The severity of pulmonary CT changes in tuberculosis also varies greatly, with the milder cases showing mainly patches, nodules, cords, or tuberculomas or isolated cavities, while the more severe cases may show lobar infiltrates, caseous pneumonia, multiple cavity formation, and bronchial dissemination.