Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is top normal . The aorta is slightly unfolded . Mediastinal and hilar contours are otherwise unremarkable . There is no pulmonary edema . Patchy opacities are demonstrated in both lung bases , without a focal consolidation seen . No pleural effusion or pneumothorax is present . Linear opacity within the right upper lobe may reflect scarring or subsegmental atelectasis . No acute osseous abnormality is identified .
    OUTPUT:
    
Patchy bibasilar opacities likely atelectasis .