Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bilateral patchy opacities worse in the midlung zone . Lung based opacity are not significantly changed from ___ , most confluent in the retrocardiac region . The cardiomediastinal silhouette is unchanged . No evidence of pneumothorax .
    OUTPUT:
    
Bilateral patchy opacities are not significantly changed from ___ .