Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral chest radiographs were obtained . The lungs are slightly low in volume but in total clear aside from linear left basilar and hazy right basilar opacities , in total , unchanged from multiple previous examinations . Opacity on the lateral is likely due to large hiatal hernia . There is no pleural effusion or pneumothorax . The heart is normal in size with tortuous aortic contour . Dual lead pacemaker , median sternotomy wires and valvular prosthesis are demonstrated .
    OUTPUT:
    
No acute intrathoracic process . Large hiatal hernia , unchanged