Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Mild cardiomegaly again noted . The aorta is unfolded with unchanged mediastinal contour . A retrocardiac opacity containing an air - fluid level is consistent with a hiatal hernia . There is mild left lower lobe compressive atelectasis related to this hernia . No evidence of pneumonia or edema . No large effusion or pneumothorax . Bony structures are intact .
    OUTPUT:
    
Mild cardiomegaly , unchanged hiatal hernia .