In the present invention, an integrated scintillator and collimator array for a detector utilized in a CT imaging system is provided. The integrated scintillator and collimator assembly is are fabricated from a manufacturing process or technique in which a scintillator array including a number of scintillation pixels is optically measured to determine the precise position of each pixel on the array. A transition material is applied to the array in a 3D printing method using the position data from the optical measurement and in subsequently bonded thereto in a sintering process to form a transition material layer. A collimator material is then 3D printed onto the transition material layer using the optical measurement data to form collimator plates on the array in alignment with the pixels thereby forming a unitary scintillator/collimator assembly for use in a detector for a CT imaging system.