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

CLINICAL/METHODICAL ISSUE: 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.

STANDARD RADIOLOGICAL METHODS

The technology of the systems is well developed so that they have become a competing method to CT imaging in terms of image quality and radiation exposure.

PERFORMANCE

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.

ACHIEVEMENTS

Advantages of these systems are that they can be used for imaging in a better 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 a horizontal 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 a small increase in the radiation exposure of patients, a trend which is reflected in the annual reports of the Federal Office for Radiation Protection.