Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung bases are partially obscured by overlying pulse generator devices bilaterally . There is no pneumothorax . Opacity at the left lung base most likely represents atelectasis , but infection can not be excluded in the appropriate clinical setting . There is also subtle opacification of the left apex , which may represent pleural scarring . No large pleural effusions are seen . Cardiomediastinal silhouette is within normal limits . Median sternotomy wires are intact . Patient is kyphotic . No acute osseous abnormalities are identified . Surgical clips are seen in the epigastric region .
    OUTPUT:
    
Left lung base opacity most likely represents atelectasis , but infection or aspiration should be considered in the appropriate clinical setting . No large pleural effusions .