Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Improving postoperative appearance of left upper lobe with better aeration and decreased opacities likely atelectasis or postoperative lung contusion . Mild elevation of the left hemidiaphragm . Previously noted air-fluid level in the left upper lobe is resolved . No focal consolidation . No pleural effusion or pneumothorax is seen . Cardio mediastinal contours are normal .
    OUTPUT:
    
Improving postoperative appearance of left upper lobe with better aeration and decreased opacities likely atelectasis or postoperative lung contusion .