Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Evaluation is limited by patient rotation . Left - sided Port - A - Cath tip terminates at the junction of the SVC and right atrium . Heart size appears grossly unchanged , borderline enlarged . Mediastinal contour is similar . There are low lung volumes with crowding of bronchovascular structures but no overt pulmonary edema is present . There is interval improvement in aeration of the right lung base , with minimal residual patchy opacities in both lung bases which may reflect atelectasis . No new focal consolidation , pleural effusion or pneumothorax is present . Dense tubular structure is noted within the region of the right internal jugular vein , unchanged
    OUTPUT:
    
Improved aeration of the right lung base with residual bibasilar atelectasis .