Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were obtained . Heart is normal in size and cardiomediastinal contour is notable for a curvilinear density along the right cardiophrenic angle , sharply marginated , present on prior studies , likely representing a hiatal hernia . The lungs are clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No acute intrathoracic abnormality .