An imaging system is provided. A method for installing the imaging system is provided. The imaging system may include a first modality imaging apparatus. The first modality imaging apparatus may have a detector including a scintillator unit, a photodetector unit, a circuit unit, a supporting block, and a supporting board. The supporting block may be disposed on an end of the scintillator unit. The supporting board may be disposed between the photodetector unit and the circuit unit.