Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal lateral views of the chest . Linear opacity at the left lung base is compatible with scarring . Additional retrocardiac opacity seen and could be due to atelectasis or scarring as well . The lungs are otherwise clear of consolidation or effusion . Surgical clips again noted in the mediastinum . Posttraumatic changes seen along the right chest wall . Hypertrophic changes noted in the spine .
    OUTPUT:
    
No definite acute cardiopulmonary process . Left lung base opacities in part due to scarring and likely atelectasis , noting superimposd infection is not completely excluded .