Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared with the prior radiograph , previous patchy and nodular opacities in the right lung have essentially resolved . Residual bibasilar opacities could be due to atelectasis , or pneumonia , in the correct clinical setting . There is mild cardiomegaly and persistent left apical pleural thickening . No pleural effusions or pneumothorax .
    OUTPUT:
    
Bibasilar opacities are likely due to atelectasis , but superimposed infection is not excluded in this clinical setting .