CT system and detection device for CT system

A detection apparatus for a CT system, comprising:

• a first layer detector assembly, a second layer detector assembly, . . . , and a N-th layer detector assembly being stacked, where N is an integer greater than 2;
• wherein the first layer detector assembly comprises a plurality of rows of first detectors arranged along a predetermined trajectory, the second layer detector assembly comprises a plurality of rows of second detectors arranged at intervals along the predetermined trajectory, . . . , and the N-th layer detector assembly comprises a plurality of rows of N-th detectors arranged at intervals along the predetermined trajectory;
• an energy corresponding to an energy response peak of the first detectors, an energy corresponding to an energy response peak of the second detectors, . . . , and an energy corresponding to an energy response peak of the N-th detectors successively decrease;
• a number of rows of detectors in a (k+1)-th layer detector assembly is smaller than a number of rows of detectors in a k-th layer detector assembly, where k=1, 2, . . . , N−1;
• and
• each row of the detectors in the (k+1)-th layer detector assembly covers a row of the detectors in the k-th layer detector assembly.