Methods and systems for CT balance measurement and adjustment

A computed tomography (CT) system comprising:

• a gantry having a rotor;
• a ray source configured to generate a plurality of rays;
• a detector configured to detect rays;
• a controller, in communication with the ray source, configured to control the gantry to perform a test scan along an optical path of the CT system, the optical path being a path along which the plurality of rays pass from the ray source to the detector;
• and
• a processor, in communication with the detector and the controller, configured to:
• obtain data obtained from the test scan;
• determine a status characteristic index of the optical path or an amount of dynamic imbalance of the gantry based on the data relating to the test scan;
• analyze the status characteristic index or the amount of dynamic imbalance;
• and
• determine whether the optical path is abnormal based on a result of the analysis of the status characteristic index, or determine whether a dynamic balance of the gantry satisfies a requirement based on a result of the analysis of the amount of dynamic imbalance,
• wherein the test scan includes two scans on an object at a first rotating speed of the rotor and at a second rotating speed of the rotor, respectively,
• wherein the determining the amount of dynamic imbalance of the gantry based on the data relating to the test scan includes:
• obtaining projection data of the two scans, respectively, each scan corresponding to a projection position of the object on the detector;
• and
• determining the amount of dynamic imbalance by determining, based on the projection data, a difference between the projection positions, and
• wherein the determining whether the dynamic balance of the gantry satisfies the requirement based on the result of the analysis of the amount of dynamic imbalance includes:
• determining whether the dynamic balance of the gantry satisfies the requirement based on the difference between the projection positions.