Aims : to provide a detailed overview of various patterns on (high-resolution) computed tomography chest imaging of patients with interstitial lung diseases and various infections; to summarise the role of radiology in evaluation of pulmonary hypertension and the role of different imaging modalities in assessment of solitary pulmonary nodules will be discussed; to review throughout the course, the size, appearance and distribution of different opacities because they are related to various differential diagnoses in clinical settings; to provide basic guidelines for differential diagnosis and an algorithmic approach to various lung and chest pathologies based on clinical history and distribution, as well as the presence of associated abnormalities.