Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette size is normal . The aortic knob is calcified . The mediastinal and hilar contours are within normal limits . Patchy ill - defined opacity is noted within the periphery of the left lower lobe . There is no pleural effusion or pneumothorax . Multilevel degenerative changes are seen in the thoracic spine . Partially imaged is a inferior vena cava filter .
    OUTPUT:
    
Peripheral left lower lobe opacity is concerning for pneumonia . Follow up radiographs are recommended to ensure resolution of this finding .