Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is moderately enlarged . Mediastinal contour is unremarkable . There is mild central pulmonary vascular congestion without frank interstitial edema . Retrocardiac density is noted and is concerning for early LLL pneumonia . The remainder of the lung fields are clear . There is no large effusion or pneumothorax .
    OUTPUT:
    
Retrocardiac density is not well assessed , though is suspicious for an early LLL pneumonia . Recommend follow - up examination to ensure resolution . Lateral views may be helpful for characterization .