Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The main reason for the left lower lobe opacity is due to small pleural effusions and atelectasis . Mild cardiac congestion is unchanged . There is no pneumothorax . Left hemodialysis catheter ends in mid SVC . Mediastinal and cardiac contours are top normal .
    OUTPUT:
    
The main explanation for the left lower lobe increased density is due to layering pleural effusion and atelectasis . Superimposed pneumonia can not be excluded .