Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral images were obtained with patient in semi-upright position . There are low lung volumes likely due to poor inspiration . The patient is also in a slightly lordotic position . There is a retrocardiac opacity that may be related to poor inspiration or overlying soft tissues , but in the appropriate clinical setting this opacity would be concerning for possible pneumonia . There is no pneumothorax or pleural effusion . Heart size is normal . Visualized osseous structures are unremarkable .
    OUTPUT:
    
Retrocardiac opacity , possibly consistent with low lung volumes or overlying soft tissue , but could also represent pneumonia in the appropriate clinical setting .