Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: No focal consolidation , pleural effusion , or pneumothorax is seen . Linear retrocardiac densities were seen previously and may represent atelectasis . Lung volumes are low , exaggerating pulmonary vasculature and hila . Heart and mediastinal contours appear similar compared to prior . There is no evidence for free intraperitoneal air below the diaphragms .
    OUTPUT:
    
Low lung volumes without radiographic evidence for acute process . Bibasilar atelectasis . No evidence of free air beneath the diaphragms .