Dose

Abstract

The gain in diagnostically valuable information accompanying the advent of computed tomography (CT) was considered to be exceptional. This is one of the main reasons why the applied dose was not considered to be of vital importance during this developmental stage. Based on the number of devices currently installed in Germany and an average of 3,500 examinations per year, an annual total number of several hundreds of millions of slices can be estimated to be acquired each year. This approximately lies within the same range as the total number of standard projection radiographs acquired in clinical practice. Considering the different types of radiological examinations (X-ray examinations), one immediately becomes aware of the following discrepancy. Although CT examinations represent only about 4% of all radiological examinations, their share of the total dose amounts up to approximately 35%. In short, CT accounts for the largest portion of medically related X-ray exposure.