Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Two views of the chest . Lungs are low in volume , but clear with decrease in previously seen retrocardiac opacity compatible with resolution of the prior opacity . Moderate hiatal hernia is unchanged . Heart and mediastinal contours are normal . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No acute intrathoracic process . Resolution of prior left lower lobe opacity .