Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is mild bibasilar atelectasis ; otherwise , the lungs are clear . There is a linear density lateral to the descending aorta of unclear etiology . Additionally , there is a second density lateral to the aortic arch of unclear etiology . Cardiac and mediastinal silhouettes are otherwise within normal limits . Diffuse osteopenia is noted with no evidence of acute fracture .
    OUTPUT:
    
There is a linear density lateral to the descending aorta of unclear etiology . Additionally , there is a density lateral to the aortic arch . These findings are nonspecific and a dedicated Chest CT is recommended for further evaluation .