While<unk> s are a relatively cheap and safe method of investigating diseases of the<unk> , there are a number of serious<unk>  conditions that may be associated with a normal<unk>  and other means of assessment may be necessary to make the diagnosis. For example, a patient with an acute myocardial infarction may have a completely normal<unk> .
Chest radiograph
Post bronchodilator test
Thoracoscopy
Bronchoscopy
CT pulmonary angiogram
Sputum culture
Lung biopsy
Bronchography