Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable upright chest radiograph demonstrates minimal left base opacity most consistent with atelectasis . There is no effusion or pneumothorax . The cardiac silhouette is normal , the mediastinal contours are normal . The pulmonary vasculature is normal .
    OUTPUT:
    
Minimal basilar atelectasis , without acute chest pathology .