Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph was provided . Lower lung bandlike opacities are noted bilaterally which could represent atelectasis , less likely aspiration . Otherwise the lungs appear clear . Limited evaluation of the cardiac silhouette is unrevealing . The mediastinal contour appears normal . No large effusion or pneumothorax . Subtle deformities along the poster lateral arch of left ___ and 10th ribs appear chronic .
    OUTPUT:
    
Bandlike opacities in the lower lungs are most compatible with atelectasis .