The present invention provides an imaging system comprising an imaging ring system with carriage ring fixed to the carriage, first rotatable ring carrying a first imaging unit, and second rotatable ring carrying a second imaging unit, wherein the first and second rotatable rings are configured to be rotated independently from each other on the carriage ring. Preferably, the first imaging unit is a radiation source and the second imaging unit is a radiation detector. The carriage ring is mounted to a carriage which is guided along the longitudinal direction of a patient couch by guiding means. The invention further provides a patient positioning system for use in a medical intervention. The system comprises a robotic arm having six axes, wherein a patient couch is fixed to the robotic arm via a C-shaped bow. The legs of the C-shaped bow extend in a direction substantially parallel to the longitudinal extension of the patient couch, one end of the C-shaped bow being fixed to a longitudinal end of the patient couch and the other end of the bow being fixed to the robotic arm. The robotic arm is configured to position a patient arranged on the patient couch in six degrees of freedom with respect to a medical treatment or examination device. The robotic arm is ceiling mounted. According to a preferred embodiment of the invention the guiding means of the imaging system are fixed to the patient couch of the patient positioning system.
