Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Cardiomediastinal silhouette and hilar contours are unremarkable . Subtle reticulation at the lung bases was seen previously in a similar distribution . The lungs are otherwise clear . Pleural surfaces are clear without effusion or pneumothorax .
    OUTPUT:
    
Subtle reticulation at the lung bases appears identical to prior examinations , likely representing trace interstitial edema .