Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Lateral view is limited due to patient arm position over the chest . Lung volumes are low though allowing for this the lungs appear clear . No definite pleural effusion or pneumothorax is seen . Heart size is difficult to assess due appears grossly stable . Mediastinal prominence likely due to unfolded thoracic aorta , intervally progressed . No acute bony abnormalities .
    OUTPUT:
    
Unfolded thoracic aorta likely accounts for interval development of mediastinal prominence . Low lung volumes without definite sign of acute intrathoracic process .