Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest demonstrate slight interval increase in interstitial markings , consistent with mild interstitial pulmonary edema . Small left apical pneumothorax and small left pleural effusion are unchanged . Cardiomediastinal and hilar contours are unchanged .
    OUTPUT:
    
1 . Small left apical pneumothorax and small left pleural effusion are unchanged . 2 . Slight interval increase in interstitial markings , consistent with mild interstitial pulmonary edema .