Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is moderate to severe diffuse increase in interstitial markings bilaterally which may be due to severe chronic lung disease , and / or pulmonary edema , atypical infection not excluded . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
Moderate to severe diffuse increase in interstitial markings bilaterally . Differential diagnosis includes pulmonary edema , and / or severe chronic lung disease , atypical infection not excluded .