text: <unk>  can present with a various range of symptoms from sudden acute chest pain, shortness of breath, cough to no symptoms at all. Diagnosis of<unk>  depends on the associated or precipitating condition. On physical exam,<unk>  is associated with a specific sign known as Hamman's sign, which is the presence of mediastinal crunch or click present on auscultation over the cardiac apex and the left sternal border synchronous with the heartbeat.<unk>  can routinely be diagnosed by chest X-ray.<unk>  investigation of<unk>  for<unk>  is CT-scan of the chest.
option_0: Pneumomediastinum diagnostic study of choice
option_1: Pneumothorax diagnostic study of choice
option_2: Hemothorax diagnostic study of choice
option_3: Hemoptysis diagnostic study of choice
option_4: Pulmonary edema diagnostic study of choice
option_5: Aspiration pneumonia diagnostic study of choice
option_6: Pleural effusion diagnostic study of choice
option_7: Hemothorax echocardiography or ultrasound