Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph ___ at 15 :01 is submitted .
    OUTPUT:
    
Interval decrease in size of the left pleural effusion status post thoracentesis with residual patchy opacity at the left base likely reflecting compressive atelectasis . Lung volumes remain low . No pneumothorax or pulmonary edema . Overall cardiac and mediastinal contours are within normal limits .