Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy and CABG . Left - sided pacemaker device is again noted with leads terminating in the right atrium and right ventricle . Endotracheal tube tip is in standard position terminating approximately 4 .4 cm from the carina . Lung volumes are low . Heart size is accentuated as a result appearing mildly enlarged . Aortic knob is calcified . Mediastinal contours are grossly unremarkable . There is crowding of bronchovascular structures with mild pulmonary vascular congestion . Patchy airspace opacities in the lung bases may reflect atelectasis , however , infection or aspiration can not be excluded . There is likely a trace right pleural effusion . No pneumothorax is detected . There are no acute osseous abnormalities .
    OUTPUT:
    
Low lung volumes with patchy airspace opacities in the lung bases , potentially atelectasis , but infection or aspiration can not be excluded . Probable trace right pleural effusion and mild pulmonary vascular congestion .