CT scanning is the modality of choice in evaluating the lungs and soft tissues of the chest (the mediastinum). All diseases of the lungs, including infectious diseases (pneumonia), neoplastic diseases (cancer) and chronic inflammatory diseases (fibrosis) are well demonstrated with CT scanning. IV contrast is not usually necessary for imaging the lung tissue itself.
The central soft tissues of the chest (the mediastinum) are also best evaluated with CT, and contrast is generally useful. The blood vessels of the chest, including the aorta and the pulmonary artery, are well evaluated using CT angiography. This is essentially a CT scan of the chest with IV contrast. These exams are sensitive in detecting diseases of the aorta such as aneurysm or dissection, and diseases of the pulmonary artery such as embolism.
See our section on CT Coronary Angiography to read more about this new technology.