Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Small - to - moderate right pleural effusion , new since the ___ CT . A lower lobe opacity is incompletely localized on the frontal view . Cardiac size and mediastinal contours are unremarkable .
    OUTPUT:
    
Lower lobe opacity could reflect atelectasis or pneumonia with an anteriorly positioned small - to - moderate right pleural effusion . Radiograph in ___ weeks after treatment is recommended to assess resolution . Findings were discussed with ___ , NP , by Dr . ___ by phone at ___ on ___ .