Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . The heart remains moderately enlarged with retrocardiac opacity compatible with known hiatal hernia . Left lower lobe is poorly assessed due to poor penetration . Elsewhere the lungs appear clear . No large effusion or pneumothorax . Mediastinal contour stable . No acute bony injury .
    OUTPUT:
    
Retrocardiac opacity compatible with known hiatal hernia . Moderate cardiomegaly . Otherwise unremarkable . If there is strong clinical concern for rib fracture a dedicated rib series is recommended to further assess .