Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs demonstrate stable cardiomediastinal and hilar contours . No cardiomegaly evident . There are new bibasilar opacification , left greater than right , which may be related to worsening chronic lung changes given the appearance of background emphysema ; however , developing infectious process is a consideration . No pleural effusion or pneumothorax evident . No osseous abnormality evident .
    OUTPUT:
    
Background emphysematous changes . New bibasilar opacifications left greater than right may reflect worsening chronic lung disease , though a developing infectious process or aspiration are considerations .