Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Overlying EKG leads are present somewhat limiting assessment . There is linear opacity in the left lower lung , likely atelectasis . Otherwise lungs appear clear . Cardiomediastinal silhouette is unchanged with atherosclerotic calcification of the aortic knob . Bony structures appear grossly intact . Clips in the right upper quadrant noted .
    OUTPUT:
    
Presumed atelectasis of the left lung base , otherwise unremarkable .