Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are slightly low . Relatively linear opacities at the left lung base with obscuration of the left costophrenic angle , potentially atelectasis . Elsewhere , lungs are clear . The cardiomediastinal silhouette is within normal limits . Atherosclerotic calcifications are noted at the aortic arch . No acute osseous abnormalities .
    OUTPUT:
    
Relatively linear left basilar opacities potentially atelectasis in the setting of low lung volumes . Infection or aspiration is not entirely excluded .