Comparative study of image quality and radiation dose of cone beam and low-dose multislice computed tomography - an in-vitro investigation

Abstract

The aim of this study was to evaluate the image quality and dose exposition of different cone-beam computed tomography (CBCT) and low-dose multislice spiral CT (MSCT) scanners. A human cadaver head was examined with three MSCT and five CBCT scanners. The radiation dose was measured using an Alderson RANDO phantom. Standard protocols were used to obtain the CBCT data. For the MSCT devices, the tube voltage and tube current were modified to obtain acceptable image quality while keeping the radiation dose as low as possible. The image quality of MSCT and CBCT devices was determined by examining the enamel-dentin and dentin-pulp interface and the periodontal ligament space of 22 teeth. Inter- and intra-observer agreement was found for the different groups of raters. CBCT systems were rated superior to MSCT devices in terms of image quality for all dental structures. The differences in image quality among the studied CBCT and MSCT scanner groups did not turn out to be significant but were significant between CBCT and MSCT devices. The organ dose varied considerably between the different CBCT and MSCT devices. The differences concerning the organ dose were notably pronounced in the area of the eye lens. The tested devices exhibited significant differences with respect to the organ dose. The variance was particularly pronounced in the CBCT devices. With a dose exposition equal or lower than the CBCT, the image quality in the MSCT devices was judged to be significantly worse.