Effect of Different Rotation Angle on Image Quality in Dental CBCT: Physical Evaluation

Abstract

Dental cone beam computed tomography (CBCT) is now widely available withboth 180° and 360°imaging. Radiation dose and motion artifacts are lower for 180° than 360° imaging. Therefore, 180° imaging may be useful in children who are more sensitive toradiation exposure and have difficulty in controlling their body movements. Thepurpose of this study was to clarify the effect of rotation angle on imagequality from modulation transfer function (MTF) and noise power spectrum (NPS) and to determine the optimal imaging tube voltage byobtaining the tube voltage characteristics of FPD. As a result, resolution wasnot affected by rotation angle. NPS was higher in 180°imaging than in 360° imaging. System performance (SP) function was lower in 180° imaging than in 360° imaging, withoutchanging the frequency characteristics. The higher the tube voltage, the higherthe value of SP function and the lower the radiation dose. The optimal tubevoltage for dental CBCT will be 90 kV.