Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomediastinal silhouette including cardiomegaly is stable . The central pulmonary arteries are enlarged . The azygos vein is engorged . There is no focal consolidation , pleural effusion , or pneumothorax . There is no pulmonary edema .
    OUTPUT:
    
1 . No substantial change compared to the prior examination . 2 . Enlargement of the pulmonary arteries , heart , and the azygos vein is consistent with pulmonary arterial hypertension . 3 . No evidence of pneumonia or pulmonary edema .