Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to ___ , atelectasis of right lung base is improved and left lung base is increased . Evaluation for pneumonia is difficult due to the chronic interstitial changes at bilateral lung bases . There appears to be focal area of opacification in the right base , which may be pneumonia in correct clinical setting . There is minimal left pleural effusion . Pulmonary vessel congestion is mild . Cardiomediastinal silhouette is normal size .
    OUTPUT:
    
Evaluation for pneumonia is difficult due to the chronic interstitial changes at bilateral lung bases . There appears to be focal area of opacification in the right base , which may be pneumonia in correct clinical setting .