Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiographs were obtained . Lung volumes are low . There is increased bilateral hilar and interstitial opacity and septal lines . There is no focal consolidation , effusion , or pneumothorax . Cardiac and mediastinal contours are normal . VP shunt catheter tubing appears intact .
    OUTPUT:
    
Low lung volumes . Moderate interstitial edema .