Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: An overlying trauma board and support devices obscure the image . The heart and mediastinal contours are normal . There are multiple displaced acute left rib fractures and old bilateral lower rib fractures . A medial left clavicle fracture and a left scapular fracture are identified . Increased density throughout the left hemithorax may represent a layering effusion . There is no large pneumothorax .
    OUTPUT:
    
Multiple displaced left rib fractures , left medial clavicle fracture and left scapular fracture . Increased density throughout the left hemithorax may represent a layering effusion .