Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear unchanged . There is no pleural effusion or pneumothorax . A moderate interstitial abnormality appears to have mildly worsened and suggests pulmonary edema that is superimposed on background interstitial lung disease .
    OUTPUT:
    
Moderate interstitial abnormality suggesting pulmonary edema in addition to background interstitial disease .