Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph was provided . The lungs are clear bilaterally without focal consolidation , effusion or pneumothorax . Nodular opacities project over the lower lungs likely representing nipple shadows . No large effusion or pneumothorax . A retrocardiac density is compatible with known hiatal hernia . The heart and mediastinal contours are normal . Bony structures appear intact .
    OUTPUT:
    
No acute findings in the chest .