The calcaneal quantitative ultrasound is used primarily for bone density screening. The Imaging Center of UWS utilizes the Achilles InSight Ultrasonometer to measure ultrasound variables of the calcaneus to provide a clinical measure called the Stiffness Index. The Stiffness Index results are expressed as T-scores to assist physicians in the diagnosis of osteoporosis the same way as the T-scores are obtained by x-ray absorptiometry.