Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are normal . Pulmonary vasculature is normal . Minimal blunting of the left costophrenic angle could be due to a trace pleural effusion . Lungs are clear . No pneumothorax is identified . There are moderate multilevel degenerative changes in the thoracic spine with anterior osteophyte formation .
    OUTPUT:
    
Trace left pleural effusion . No evidence of pneumonia .