Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest demonstrate normal lung volumes . Linear opacity involving the left lung base likely represents atelectasis . Hilar and mediastinal silhouettes are unremarkable . Heart size is normal . There is no pulmonary edema . No pneumothorax is seen . Partially imaged upper abdomen is unremarkable .
    OUTPUT:
    
No acute cardiopulmonary process .