Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is mildly enlarged . The hilar and mediastinal contours are unremarkable , except for moderate calcification in the aortic knob . Extensive interstitial opacities are seen in both lungs , most extensively in the right lung base and left mid lung . While these changes could represent chronic interstitial lung disease , superimposed mild pulmonary edema can not be excluded without a baseline radiograph for comparison . No large pleural effusions or pneumothorax are seen .
    OUTPUT:
    
Extensive interstitial abnormalities in both lungs , with more confluent opacity in the right lower and left mid lung . While these changes likely reflect chronic interstitial lung disease , superimposed mild interstitial edema is difficult to exclude given the lack of baseline studies for comparison .