Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single frontal image of the chest was obtained . Lung volumes are low . This is accentuating the bronchovascular structures and heart size , which are likely normal . There is an enlarged azygous vein which is suggestive of an elevated central venous pressure . There is no definite pulmonary edema . The left costophrenic angle is obscured , possibly due to a small left pleural effusion . There is no pneumothorax .
    OUTPUT:
    
1 . Very limited exam due to low lung volumes . 2 . Enlarged azygous vein suggests elevated central venous pressure , for which the differential diagnosis is isolated right heart failure , a pericardial effusion , or a large pulmonary embolism . 3 . Probable small left pleural effusion . Results were discussed with Dr . ___ ___ resident ) at 9 : 20 a .m . on ___ via telephone by Dr . ___ .