Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP chest radiograph demonstrates no focal consolidation , pleural effusion , or pneumothorax . The main pulmonary artery is enlarged with paucity of peripheral vascular markings , compatible with oligemia from extensive pulmonary emboli , as noted on the CTA . The cardiomediastinal silhouette is normal .
    OUTPUT:
    
Dilated main pulmonary artery with oligemia of the peripheral pulmonary vasculature ( ___ Sign ) compatible with known extensive saddle pulmonary embolism .