Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single portable AP chest radiograph was obtained . Lung volumes are low . The lungs are clear . There is no focal consolidation , effusion or pneumothorax . Heart size is still normal , but azygous and mediastinal veins are mildly dilated , perhaps an indication of right heart dysfunction or other cause of elevated central venous pressure . Clinical correlation would be wise .
    OUTPUT:
    
Possible right heart dysfunction or other cause of elevated central venous pressure .