Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lungs are well inflated and clear save for a single linear irregularly shaped opacity within the left upper lung zone most likely mild subsegmental atelectasis . There is no consolidation concerning for infection . No masses or lesions are seen . There is no pleural effusion or pneumothorax . The cardiomediastinal silhouette is normal . The pleural surfaces are unremarkable .
    OUTPUT:
    
No evidence of infection or malignancy . CT scanning is more sensitive for detection of small lung nodules .