Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal contours are remarkable for enlarged main pulmonary artery contour suggesting pulmonary arterial hypertension . Additionally , a well - circumscribed right cardiophrenic angle opacity corresponds to an area of increased pericardial fat or a fat - containing Morgagni hernia on prior CTA of the chest . Lungs are clear . Small left pleural effusion is evident on the lateral view .
    OUTPUT:
    
1 . No acute lung abnormality . 2 . Enlarged main pulmonary artery suggesting pulmonary arterial hypertension . 3 . Small left pleural effusion .