Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Moderate enlargement of the heart size is again noted . The aortic knob is calcified . Mediastinal and hilar contours are unremarkable . There is mild pulmonary vascular congestion . Patchy opacities in the lung bases could reflect areas of atelectasis . Infection is not excluded . There may be a trace left pleural effusion . No pneumothorax is detected . Partially imaged is a right shoulder arthroplasty . Degenerative changes in the left glenohumeral joint are noted . No acute osseous abnormality is visualized .
    OUTPUT:
    
Mild pulmonary vascular congestion and possible trace left pleural effusion . Patchy bibasilar opacities , likely atelectasis though infection is not completely excluded .