Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs demonstrate low lung volumes , though clear lungs . There is no pleural effusion or pneumothorax . The cardiac silhouette is top normal . The mediastinal contours are notable only for tortuosity of the thoracic aorta . The pulmonary vasculature is normal .
    OUTPUT:
    
No acute chest abnormality .