Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hypoinflated with crowding of vasculature . Persistent retrocardiac opacity is unchanged over multiple examinations and consistent with known hiatal hernia . No pleural effusion or pneumothorax . There is persistent mild cardiomegaly , likely accentuated due to low lung volumes . Mediastinal contour and hila are unremarkable .
    OUTPUT:
    
1 . Hypoinflated lungs . 2 . Retrocardiac opacity is consistent with hiatal hernia . 3 . Stable mild cardiomegaly .