Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded . In the retrocardiac area on the lateral image , there is increased opacity , which could represent atelectasis , or possibly pneumonia or sickle lung in the right clinical setting . There is small left pleural effusion . The there is no pneumothorax . The cardiomediastinal silhouette is unremarkable . A right - sided central line catheter terminates in the right atrium . Sclerosis in the left humeral head and mildly H - shaped veterbrae aer seen , consistent with known sickle cell disease .
    OUTPUT:
    
Left retrocardiac opacity , which could represent atelectasis , pneumonia or sickle lung in the appropriate clinical setting .