Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . Subtle medial right basilar opacity may be due to atelectasis , although it is more prominent as compared to the prior study . No pleural effusion is seen . No pneumothorax is seen . Cardiac and mediastinal silhouettes are stable .
    OUTPUT:
    
Patchy medial right basilar opacity may be due to atelectasis and confluence of vascular structures ; however , infectious process is not excluded in the appropriate clinical setting .