Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal silhouette and pulmonary vasculature are unremarkable and unchanged since the prior examination . There is no pleural effusion or pneumothorax . Right perihilar linear density is consistent with atelectasis . No free intraperitoneal air .
    OUTPUT:
    
No acute intrathoracic process .