New sophisticated imaging techniques have enabled quantitative and functional thoracic imaging. Chest radiography has become more commonly used in clinical diagnosis. CT is commonly used in quantitative imaging to assess pulmonary nodules, lung density, airways, and arteries. With the introduction of dual-energy CT (DECT) and functional MR, more functional information may be obtained to assess various lung illnesses. The use of chest radiography in clinical diagnosis has grown significantly with the development of computed tomography (CT) scans of the thorax, particularly with the introduction of high resolution CT (HRCT), spiral CT, and multidetector spiral CT. Each of these modalities is highly sensitive and specific in detecting various lung pathologies, such as HRCT for diffuse lung illness, spiral CT, and multidetector spiral CT for imaging airways, pulmonary and systemic arteries, and lung nodules. CT thorax with or without contrast enhancement plays a very important role in detecting pulmonary thromboembolism, mediastinal pathology, chest CT incidentalomas, pleural and chest wall pathology, metabolic and storage lung disease. And often cardiac conditions like valvular calcifications, right ventricular dilatation, and right ventricular thrombus.