Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The right lung apex and upper mediastinum are obscured by the patient 's head and neck . Allowing for this , no gross change is identified . Again seen is cardiomegaly with a dual lead pacemaker and patchy opacity at the right lung base , with minimal blunting of the right costophrenic angle , similar to the prior study . As before , the right hemidiaphragm appears elevated . Also again seen is atelectasis at the left lung base . No left no gross left effusion . Upper zone redistribution again noted . Doubt overt CHF .
    OUTPUT:
    
Cardiomegaly with upper zone redistribution , similar to prior . Elevated hemidiaphragm with right base atelectasis and small right effusion , also similar to prior . In the appropriate clinical setting , the differential could include an early pneumonic infiltrate .