Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright chest radiograph demonstrates a mildly enlarged heart despite marked patient rotation . There is no evidence of pulmonary edema . There is no large pleural effusion . No focal opacity convincing for pneumonia . Air-fluid level above the hemidiaphragm is present , most conspicuous on the lateral view , likely reflective of hiatal hernia . No pneumothorax .
    OUTPUT:
    
Mild cardiomegaly without pulmonary edema . Large hiatal hernia .