Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear unchanged . A focal onodular opacity projects along the inferior left anterior first costochondral junction and left upper lung , but if this is a bony prominence , is more distinct than on the prior study . Otherwise , the lung fields appear clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
1 . No evidence of acute cardiopulmonary disease . 2 . Nodular focus projecting over the left upper lobe and course of the left anterior first rib , probably due to degenerative hypertrophy at the costochrondral junction . However , when clinically appropriate , repeat AP , AP lordotic , and bilateral oblique radiographs are recommended to reassess and exclude a lung nodule .