Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Retrocardiac opacity is poorly seen on this single view but could reflect atelectasis or developing infectious process . Lungs are somewhat low in volume giving the appearance of vascular crowding , though mild pulmonary vascular congestion is present as well . Mild right base atelectasis is noted , early infection not excluded in the appropriate clinical setting . Cardiac size is moderately enlarged with changes of prior coronary bypass graft noted . No pneumothorax or pleural effusion is seen .
    OUTPUT:
    
1 . Retrocardiac opacity incompletely assessed on this single view could reflect atelectasis or developing infectious process . Mild right base atelectasis is noted , early infection not excluded in the appropriate clinical setting . Consider PA and lateral radiographs for further evaluation . 2 . Mild pulmonary vascular congestion . Enlarged cardiac silhouette .