Digital volume tomography : Dedicated scanner and cone beam CT with C‑arm systems

Abstract

Digital volume tomography (DVT) and cone-beam computed tomography (CT) with C‑arm systems have become established three-dimensional imaging systems as an alternative to CT in some application areas. The technology of the systems is well developed so that they have become acompeting method to CT imaging in terms of image quality and radiation exposure. An advantage is the better spatial resolution, preferably with dedicated scanner systems, especially in the z direction. The radiation exposure of CT, cone beam CT and DVT are comparable, if the exposure parameter in CT imaging can be adjusted to the lower exposure levels. Advantages of these systems are that they can be used for imaging in abetter workflow or to acquire images under conditions not possible in CT, e. g. imaging under stress in orthopedics or to take images in the corona technique with ahorizontal gantry in cone-beam CT mammography PRACTICAL RECOMMENDATIONS: The use of three-dimensional imaging is becoming more frequent and will replace planar radiography in additional clinical situations. The three-dimensional imaging without superpositioning of structures has advantages in the visibility of structures and the spatial relation to other organs and structures. In guidelines and recommendations, the number of recommendations given for the use of three-dimensional imaging is increasing. This leads to asmall increase in the radiation exposure of patients, a trend which is reflected in the annual reports of the Federal Office for Radiation Protection.