Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are asymmetric nodular opacities at the right lung base . The left lung is clear . There is no pneumothorax . Cardiomegaly is mild . The mediastinal contours are normal . Metallic right upper quadrant surgical clips indicate prior cholecystectomy .
    OUTPUT:
    
Nodular opacities at the right lung base may be due to a combination of atelectasis and overlying rib shadows , but metastasis or even pneumonia are also possible . A dedicated chest CT is recommended for further evaluation . Mild cardiomegaly .