Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is left basilar atelectasis but the lungs are otherwise clear of focal opacities , pleural effusion , pulmonary edema or pneumothorax . The heart and mediastinal contours appear within normal limits . Degenerative changes are seen within the imaged spine .
    OUTPUT:
    
No radiographic evidence of pneumonia .