Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are normal . The pulmonary vascularity is normal . Consolidative opacity within the left lung base , mostly within the left lower lobe , is compatible with pneumonia . The right lung is clear . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Left basilar pneumonia . Followup radiographs after treatment are recommended to ensure resolution of this finding .