Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . The mediastinal contours are unremarkable . Left lower lobe consolidative perihilar opacity is new compared with the prior exam and is concerning for pneumonia . Right lung is grossly clear . No pleural effusion or pneumothorax is present . There are multilevel degenerative changes in the thoracic spine .
    OUTPUT:
    
Left lower lobe consolidative opacity concerning for pneumonia . Followup radiographs after treatment are recommended ensure resolution of this finding .