 Genant later published several articles on spinal QCT in the early 1980s with Christopher E. Cann, PhD.Today, QCT is being used in hundreds of medical imaging centers around the world, both clinically and as a powerful research tool.Originally, conventional 2D QCT used individual, thick CT slice images through each of multiple vertebrae which involved tilting the CT scanner gantry to align the slice with each vertebra.