Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to chest radiograph from ___ , moderate right effusion is improving . Mild left effusion has not appreciably changed . Left pleural drainage tube unchanged in standard position . Lung volumes remain low . Persistent widening of the superior mediastinum is related to chronic SVC obstruction , as seen on prior CT . No focal consolidation , vascular congestion or pulmonary edema .
    OUTPUT:
    
1 . Improving moderate right effusion . 2 . Unchanged mild left effusion . 3 . Chronic widening of the superior mediastinum is related to chronic SVC obstruction .