Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest demonstrate low lung volumes . The right lung base appears elevated , which may represent subpulmonic pleural effusion or alternatively ascites . Right lung base opacity likely represents atelectasis . Left lung is clear . Hilar and mediastinal silhouettes are unremarkable . No pneumothorax or pulmonary edema . Heart is moderately enlarged , increased from prior . Partially imaged upper abdomen demonstrates paucity of gas . Surgical clips project over right upper abdomen .
    OUTPUT:
    
1 . Moderate cardiomegaly , increased from prior exam , may represent pericardial effusion . No evidence of vascular congestion . 2 . Elevation of the right lung base is new from ___ exam , which may represent a subpulmonic pleural effusion , or subphrenic pathology , such as ascites . Right lung base opacity likely represents atelectasis .