Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is mild cardiomegaly . Lung volumes are low , exaggerating the hilar mediastinal contours , which are otherwise unremarkable . There are mild bibasilar opacities . There is an opacity overlying the right upper lung , along the mediastinum . There is no evidence of pneumothorax . The visualized osseous structures are unremarkable .
    OUTPUT:
    
1 . Bibasilar opacities may be secondary to atelectasis given low lung volumes , however acute infectious process can not be excluded . 2 . Opacity overlying the right upper lung , along the mediastinum , may be secondary to tortuosity of the great vessels , or superimposition of structures , however a CT is recommended for further evaluation to exclude malignancy .