Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single frontal chest radiograph was obtained . The lung volumes are low . Fibrotic changes at both lung bases are similar . The left costophrenic angle is blunted . Elevation of the bilateral hemidiaphragms is similar . There are no new abnormal cardiac or mediastinal contours . Calcifications of the aortic arch are unchanged .
    OUTPUT:
    
Mild blunting of the left costophrenic angle . A small effusion can not be excluded .