Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is an unchanged linear opacification at the left base , most consistent with chronic atelectasis , aspiration or scarring . There is no pulmonary edema , pleural effusion or pneumothorax . Moderate enlargement of the cardiac silhouette is stable from the prior exam . Atherosclerotic calcification is noted within a torturous aorta . Clips are noted in the mediastinum . No definite fractures identified .
    OUTPUT:
    
1 . No acute cardiopulmonary process . 2 . Chronic left lower lobe opacitiy may be due to aspiration , atelectasis or scarring .