My Son Was Playing Sports And Sustained A Blow Which

My son was playing sports and sustained a blow which injured his collarbone at the sternum. Xrays and CT scan both indicate no broken bones. He says it feels like it's dislocated as it's shifting when he lifts his arm up. Would a dislocation be present in the ct scan? Just don't want anything overlooked now. he is in a sling and taking ibroprofen for the pain.