Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes . Biapical pleural thickening . There are linear opacities at the bases bilaterally , representing atelectasis . There is a subcentimeter dense nodule , at the left apex , which represents a calcified granuloma . The lungs are otherwise clear . Heart size is stable . The mediastinal and hilar contours are stable . The pulmonary vasculature is normal . No pleural effusion or pneumothorax is seen . The patient is status post vertebroplasty at multiple thoracic and lumbar levels .
    OUTPUT:
    
Linear opacities at the bases bilaterally , which likely represents atelectasis due to low lung volumes , however aspiration can not be excluded .