Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the next most recent study , there is no significant change in bilateral interstitial abnormalities . There is no focal consolidation . There is no large pleural effusion or pneumothorax . The cardiomediastinal silhouette and hilar contours are normal .
    OUTPUT:
    
Persistent generalized interstitial abnormalities of unclear etiology . As previously suggested , findings may reflect recurrent interstitial pneumonia . If clinically indicated , CT may be obtained for further evaluation .