Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiograph demonstrate minimal atelectasis versus scarring at the left lung base . Cardiomediastinal and hilar contours are within normal limits . There is no pneumothorax or pleural effusion . Patient is status post posterior spinal fusion of the lower thoracic spine and visualized lumbar vertebrae . Osseous structures are otherwise unremarkable .
    OUTPUT:
    
No acute intrathoracic abnormality . Minimal atelectasis versus scarring at the left lung base .