 QCT was invented at University of California San Francisco (UCSF) during the 1970s.Douglas Boyd, PhD and Harry Genant, MD used a CT head scanner to do some of the seminal work on QCT.At the same time, CT imaging technology progressed rapidly and Genant and Boyd worked with one of EMI’s first whole body CT systems in the late 1970s and early 1980s to apply the quantitative CT method to the spine, coining the term "QCT."