[CT findings of pulmonary infections]

Although many pulmonary infections are diagnosed using chest radiographs in combination with clinical findings and are treated empirically with antibiotics, there are situations in which chemotherapy is not effective and further examinations are necessary. In those cases, CT, especially high-resolution CT (HRCT), can provide additional information about detailed morphological changes of the lung that are sometimes indicative of the causative organisms of pneumonia, such as pulmonary tuberculosis. Although it is true that the same organism can present a wide spectrum of radiological findings, it is also important for differential diagnosis to understand the basic features of pathological changes of the lung and the CT findings caused by each of the various organisms. Such CT information would also be useful in differentiating infectious pneumonia from noninfectious pneumonia. This review article presents the principal CT findings of pulmonary infections and their pathological correlations with various pneumonias, including bacterial, tuberculous, fungal, and viral pneumonias.