The advent of computed tomography (CT) has revolutionized radiology. Starting as head-only scanners, modern CT systems are now capable of performing whole-body examinations within a couple of seconds in isotropic resolution. Technical advancements of scanner hardware and image reconstruction techniques are reviewed and discussed in their clinical context. These improvements have led to a steady increase of CT examinations in all age groups for a number of reasons. On the one hand, it is very easy today to obtain whole-body data for oncologic staging and follow-up or for trauma imaging. On the other hand, new examinations such as cardiac imaging, virtual colonoscopy, gout imaging, and whole-organ perfusion imaging have widened the application profile of CT. The increasing awareness of risks associated with radiation exposure triggered the development of a variety of dose reduction techniques. Effective dose values below 1 mSv, less than the annual natural background radiation (3.1 mSv/year on average in the United States), are now routinely possible for a number of dedicated examinations, even for coronary CT angiography.
From the *Department of Radiology, University Hospital Erlangen, Erlangen, Germany; †Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands; ‡Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland; §Department of Medical Physics, University of Crete, Iraklion, Crete, Greece; and ∥X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Received for publication February 20, 2015; and accepted for publication, after revision, April 8, 2015.
The authors report no conflicts of interest.
Correspondence to: Michael M. Lell, MD, Department of Radiology, University of Erlangen-Nuremberg, Ulmenweg 18, 91054 Erlangen, Germany. E-mail: email@example.com.