Peripheral quantitative computed tomography and micro-computed tomography

Bone mineral density (BMD) of the central and peripheral skeleton can be evaluated with a high degree of accuracy and precision using quantitative computed tomography (QCT). This chapter reviews a special group of QCT systems, peripheral quantitative computed tomography (pQCT), developed for volumetric bone mineral assessment at the peripheral skeleton in both humans and various animals models. QCT is an established technique for determination of bone mineral density in axial spine and appendicular skeleton such as the forearm and tibia. A basic pQCT machine operates on second generation computed tomography (CT) scanning principles. The pQCT machine consists of two major components, the scanner hardware and a computer system for hardware control and image data analysis. Using pQCT, age-related bone loss can be studied separately for total, cortical and trabecular bone at the same site. pQCT is a dedicated CT system that acquires a cross-sectional image to measure BMD and BMC at peripheral sites such as the distal radius and tibia.