Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded . Left base scarring , pleural thickening as well as multiple left posterior rib deformities represent post - thoracotomy changes , unchanged from prior . No focal parenchymal opacity concerning for pneumonia . There is no pleural effusion or pneumothorax . There is no cardiomegaly . Cardiomediastinal and hilar contours are unremarkable .
    OUTPUT:
    
Post thoracotomy changes in the left hemithorax unchanged from prior . No focal parenchymal opacity concerning for pneumonia .