Technology and principles of cone beam computed tomography

This chapter aims to convey a basic technical familiarity with compact Cone Beam Computed tomography (CBCT) systems, which have become prevalent since the late 1990s as enablers of in-office CT imaging of the head and neck. The first section provides a high-level overview of these systems with a discussion of their basic hardware components and their emergence as an alternative to conventional, hospital CT. The second section gives a treatment of imaging basics, including various aspects of how a CT image is derived, manipulated, and evaluated for quality. It describes the image processing software components of compact CBCT systems that go into action once X-ray measurements have been acquired, and provides a short introduction to emerging iterative reconstruction methods and some rudimentary demonstrations. It also discusses several quantitative measures of image quality that are commonly used to assess the performance of a CT device.