Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph ___ at 03 :28 is submitted .
    OUTPUT:
    
Interval appearance of patchy opacity at the left base with associated effusion which would be concerning for aspiration or pneumonia , less likely contusion . Right lung remains grossly clear . Overall cardiac and mediastinal contours are stable . No pneumothorax . No pulmonary edema . No displaced rib fracture is seen , although a dedicated rib series would be more sensitive if this is of clinical concern .