Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The visualized mediastinal structures are unremarkable . There is no cardiomegaly . There is a new retrocardiac opacity present in the left lower lobe which is concerning for pneumonia . No associated effusions . The faintly visible right mid lung opacity projecting over the posterior seventh rib is again visualized . No pneumothorax . There is a right sided PICC line with distal tip projecting over the upper SVC .
    OUTPUT:
    
New retrocardiac opacity concerning for left lower lobe pneumonia .