Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single frontal view of the chest demonstrates persistent cardiomegaly , which is likely accentuated by AP technique . There is apparent widening of the mediastinum , more pronounced as compared to prior exam , which could be attributed to potentially semi-supine positioning accentuating mediastinal fat . The lungs are reasonably aerated allowing for underpenetration . There is no pneumothorax , large effusion , or congestion . There is ill defined retrocardiac opacity , which likely represents atelectasis .
    OUTPUT:
    
Ill - defined retrocardiac opacity , likely represents atelectasis as the CT of the abdomen and pelvis from the same day demonstrated clear lungs . Apparent mediastinal widening which could be related to positioning , but can be further assessed if clinically indicated . Consider repeat exam with PA and lateral views at full inspiration and upright position to confirm findings . Findings discussed with Dr . ___ ___ phone at 10 p .m . on ___ .