Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The inspiratory lung volumes are decreased with resultant accentuation of bronchovascular and cardiomediastinal structures . There is a small left pleural effusion with associated left basilar opacification . There is no significant pulmonary vascular engorgement . The mediastinum is prominent in part due to unfolding of the thoracic aorta . There is minimal calcification of the aortic knob . No acute osseous abnormalities detected .
    OUTPUT:
    
Small left pleural effusion with associated left basilar opacification , which in the setting of low lung volumes may represent atelectasis .