Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiograph demonstrates hyperaerated lungs with relative lucencies of the upper lobes suggesting emphysema . There is an appearance of impproved aeration of the right lung base ; however , the minor fissure is not well seen and it is unclear if change reflects slightly worsened chronic right middle lobe collapse no longer obscuring evaluation of the right lower lung or improved collapse . Residual streaky opacification within the left lung base is consistent with atelectasis . No focal opacification concerning for pneumonia present . Cardiomediastinal and hilar contours are unremarkable .
    OUTPUT:
    
No acute intrathoracic process . Chronic bibasilar atelectasis . Background emphysema .