Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded and clear . Cardiomediastinal and hilar contours are unremarkable . There is no pleural effusion or pneumothorax . Rounded opacity projecting over the costovertebral junction of the left posterior 3rd rib may represent summation of structures although a lung or bony lesion can not be excluded . Multiple surgical clips projecting over the left hemithorax are due to prior breast procedures .
    OUTPUT:
    
Rounded opacity projecting over the costovertebral junction of the left posterior 3rd rib may represent overlapping structures although a pulmonary or bony lesion can not be excluded . Further assessment with chest CT on a non-emergent basis is recommended .