Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph ___ at 19 :42 is submitted .
    OUTPUT:
    
Interval appearance of a moderate to large right pleural fluid collection with decreased aeration in the right mid and lower lung likely reflecting compressive atelectasis , although an underlying mass or pneumonia can not be excluded . The left lung is grossly clear . Overall cardiac and mediastinal contours are likely not significantly changed given differences in positioning and technique . No pneumothorax . No pulmonary edema .