Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and aortic valve replacement . Lung volumes are low . There is mild enlargement of cardiac silhouette . The aorta remains tortuous and diffusely calcified . Convex contour to the right superior mediastinum corresponds to tortuous great vessels , unchanged . No pulmonary vascular engorgement is demonstrated . Streaky left basilar opacity could reflect atelectasis , although infection can not be excluded . No pleural effusion or pneumothorax is clearly demonstrated . No acute osseous abnormalities are visualized . Degenerative changes of both shoulders are noted with narrowed acromial humeral intervals suggestive of underlying rotator cuff disease .
    OUTPUT:
    
Low lung volumes . Patchy left basilar opacity likely reflects atelectasis though infection can not be excluded .