Radiology General 6c105347 An alternate to lead in the walls of radiology room is: A Walls made up of 3 inch concrete B Walls made up of barium plaster or barium concrete C Walls made up of 3 inch steel D All of the above High-Yield Explanation Walls made of 3" concrete, 3" x 16" of steel or 1 mm of lead, barium plaster or barium concrete will suffice to protect adjacent rooms from radiation.