[Hemoptysis: methods of localization].
Depending on the amount of bleeding, chest radiograph localises the origin of an hemoptysis in 20 to 50% of cases. Computed tomography (CT) scan of the chest is the most accurate method used to localise and identify the source of bleeding. In case of normal imaging, bronchoscopy localises the bleeding source in 40% of cases. Bronchogenic carcinoma was identified in 3% of the bronchoscopies performed for hemoptysis in patients with a normal chest roentgenogram. The evaluation of a minor hemoptysis in a patient without risk factor for a lung cancer could be limited to a CT-scan of the chest if this one is normal. If the prognosis of an idiopathic hemoptysis is generally good, the presence of a smoking history and an age over 50 years justifies a radiologic follow up to exclude a growing bronchial tumor.