Anatomical imaging system with improved detector calibration process

A method for calibrating detectors in a CT scanner, wherein the new calibration process uses a combination of slab-based and water-based calibrations. By combining both calibrations, the complexity of each procedure can be reduced which will reduce restrictions on the quality of detectors used in the scanner. The slabs can be made out of commercially available material such as acrylic, and they will require no special treatment. Combining both calibrations also reduces the number of water phantoms needed for the calibration and the complexity of the calibration algorithm. Furthermore, the slabs can be shaped based on the scanner geometry so as to optimize the slab-based calibration step.