Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Four frontal images of the chest were obtained . Two of the images demonstrate low lung volumes likely due to poor inspiration . The other two images demonstrate well - expanded lungs . There appears to be improvement of the right base opacification since previous imaging . The left - sided opacification appears similar to previous exams . There is no pneumothorax . There is no pleural effusion on the right . The cardiomediastinal silhouette is consistent with the previously identified massively unfolded aorta and aneurysmal aortic arch and proximal descending thoracic aorta . Aortic calcifications are seen . The aortic valve has been replaced with a porcine valve . Left basilar opacities prohibit full assessment of the cardiac size .
    OUTPUT:
    
Right basilar opacity improved since prior imaging . Persistent left basilar opacity . Otherwise , essentially unchanged chest radiograph from prior imaging .