Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette is borderline enlarged . The pulmonary vasculature is unremarkable and unchanged since the prior examination . Atelectasis is noted in the azygous lobe . The lungs are otherwise clear . No definite pleural effusion or pneumothorax is identified .
    OUTPUT:
    
No acute intrathoracic process .