Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-erect chest radiograph ___ at 05 :04 is submitted .
    OUTPUT:
    
Linear opacity at the left base favors subsegmental atelectasis . More patchy opacity at the right base could reflect atelectasis , although aspiration or pneumonia should also be considered . No pulmonary edema . Possible small right effusion . No pneumothorax . Overall cardiac and mediastinal contours are likely within normal limits .