Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low with resultant vascular crowding . There is no evidence of pneumonia or frank pulmonary edema . The cardiomediastinal silhouette , hilar contours , and pleural surfaces are normal . There is no pleural effusion or pneumothorax . Appearance of the aortic arch is typical for an aberrant right subclavian artery . Cervical spinal fusion hardware is partially seen .
    OUTPUT:
    
Slightly low lung volumes but no evidence of pneumonia . Appearance of aortic arch may reflect aberrant right subclavian artery .