Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Cardiac , mediastinal and hilar contours are unchanged from the recent chest CT allowing for differences in technique . Pulmonary vasculature is not engorged . Focal opacity within the left lower lobe partially reflects the known cavitary mass seen on the previous CT , with probable superimposed infection or atelectasis . Additionally , multiple scattered pulmonary nodules seen on prior CT are not as well assessed on the current exam . Trace left pleural effusion is present . No right pleural effusion or pneumothorax is present . Innumerable sclerotic metastatic lesions are again seen within the osseous structures .
    OUTPUT:
    
Patchy opacity within the left lower lobe likely reflects a combination of the patient 's known cavitary mass as well as superimposed infection or atelectasis . Trace left pleural effusion . Known bilateral pulmonary nodules are better assessed on the prior CT . Re - demonstration of diffuse sclerotic osseous metastases .