Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A large caliber left approach central venous catheter terminates in the right atrium , unchanged from prior . There is new opacification of the retrocardiac space which could reflect pneumonia or aspiration in the appropriate clinical circumstance . Atelectasis is also within the differential . Mild diffuse interstitial abnormality is unchanged compared to multiple prior radiographs . There is no large pleural effusion . No pneumothorax is evident . There is evidence of stable pulmonary hypertension and vascular engorgement , unchanged from prior . Moderate cardiomegaly is unchanged . Deformity of proximal right humerus appears chronic .
    OUTPUT:
    
1 . New retrocardiac opacity which could reflect aspiration , infection or atelectasis . 2 . Unchanged background interstitial abnormality and central vascular enlargement .