A computed tomography system has a gantry with a rotor side that can be rotated around a system axis during operation, at which at least one x-ray tube is mounted. To cool the at least one x-ray tube a liquid cooling system is equipped with a fluid volume filled with cooling liquid, the fluid volume extends over distances of different sizes from the system axis. The fluid volume is located on the rotor of the gantry and thus is exposed to centrifugal force during operation. To increase pressure in the cooling system, a flexible compensation volume and a movable mass element that rotate with the gantry are provided. The mass element is arranged such that the centrifugal force acting on the mass element during operation causes pressure to be exerted on the cooling liquid.