Real-time CT and CT fluoroscopy.

Abstract

The development of CT scanner technology in the past 10 years has brought a range of advances, including slip ring scanning, fast (sub-second) rotation times and greater computing power. These advances have been combined to allow rapid reconstruction of CT scanner data that can be updated continuously to provide crosssectional images in near real-time. CT scanning is conventionally prescriptive, with scan sequences planned in advance. Real-time scanning expands the role of CT to an interactive imaging technique. Applications of real-time CT lie in two main areas: timing and monitoring of helical scan sequences, and interventional procedures such as tissue biopsy and the drainage of fluid-filled lesions. In this paper, the use of real-time CT in interventional procedures is referred to as CT fluoroscopy. With the advantages of this new technology comes concern over doses to both patient and equipment operator, as well as the need for careful control over its use. This commentary examines the technology, applications and dosimetry of real-time CT scanning and draws out some of the important points in each of these areas.