Effect of the leaded-glasses as an exomass object on cone beam computed tomography (CBCT) images

Abstract

Objectives

To investigate the effect of artifacts in cone beam computed tomography (CBCT) arising from leaded-glasses in the exomass on detection of root fracture (RF) and MB2 and to test different image-acquisition parameters to reduce these artifacts.

Study Design

CBCT scans of a cadaver head were acquired using the 3D-Accuitomo-170 with field of view of 100 × 50 mm. The scanning parameters included three conditions: standard/high resolution, full/partial rotations, and with/without leaded-glasses. Six evaluators assessed the images for the presence of RF and MB2 as well as the overall image quality. Artifact measurement was performed at different distances from the exomass by calculating the standard deviation of gray values in 3 specified axial slices. The effects of the parameters and their interactions were evaluated using analysis of variance.

Results

The study found that various resolutions, rotation 360°/180°, and the presence/absence of the exomass did not have a statistically significant effect on the detection of RF. However, the present of exomass had a significant negative effect on identifying MB2, indicating that the readers were less able to detect MB2 when exomass were present. The effects of the rotation angles and resolutions were not statistically significant. The present of the exomass had a significant negative effect on image quality, whereas wider arc rotations and higher resolution had a significantly positive effect on image quality. Artifact intensity, as measured by standard deviation values, was highest in the closest slices to the exomass, followed by middle slices, and lowest in farther slices (P < .05).

Conclusion

The presence of metallic exomass in CBCT scans creates artifacts that lower image quality. However, the detection of RF is unaffected by these artifacts. Therefore, patients with suspected RF can wear leaded-glasses during CBCT scans to reduce radiation dose to the eye and lower the risk of developing cataracts.