Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Assessment of the chest is slightly limited by patient rotation . Heart size is within normal size limits . The aorta is mildly tortuous with atherosclerotic calcifications noted at the aortic knob . The pulmonary vasculature is normal . Lung volumes are lower compared to the previous exam . Patchy opacities within the lung bases , more so on the left , may reflect areas of atelectasis , but infection can not be completely excluded in the left lung base . There may be a trace right pleural effusion . No pneumothorax is demonstrated . Biapical pleural thickening and calcification are unchanged . The osseous structures are diffusely demineralized .
    OUTPUT:
    
Patchy opacities in the lung bases , more so on the left , may reflect areas of atelectasis but infection is difficult to exclude in the left lung base . Possible trace right pleural effusion .