Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Unchanged retrocardiac opacity reflects persistent left lower lobe pneumonia . Improved , small , bilateral pleural effusions . Improved pulmonary vascular congestion . Heart size at the upper limit of normal . Normal mediastinal and hilar contours .
    OUTPUT:
    
Persistent left lower lobe pneumonia . Improved pulmonary vascular congestion and small , bilateral pleural effusions .