Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In the left perihilar region , there is a hazy opacification consistent with pneumonia . There is no pulmonary edema , pleural effusion , or pneumothorax . The cardiomediastinal silhouette is normal . There is elevation of the left hemidiaphragm , which is stable from the prior exam .
    OUTPUT:
    
Left perihilar pneumonia . Recommend followup radiographs after treatment to ensure resolution .