Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable upright chest radiograph shows improved clarity at the left lung base compared to yesterday 's upright exam . The hemidiaphragm is now visible , suggesting significant decrease in fluid status post thoracentesis and no pneumothorax is seen . Mild , streaky interstitial opacities seen in both upper lobes and the right lung base . The descending thoracic aorta is tortuous and calcified , and the upper end of an expanded abdominal aortic stent is seen at the lower border of the film . Cardiac size is unchanged .
    OUTPUT:
    
No pneumothorax status post left thoracentesis with improved clarity at left lung base .