关键词: 锥形束CT, 硬化伪影, Mimics, 伪影指数, 对比度噪声比

Abstract: Objective    To study the effect of applying Mimics software to the correction of dental cone beam CT（CBCT）hardening artifact. Methods    Clinical and imaging data of 65 patients, who underwent dental CBCT examination in the Department of Radiology，Stomatological Hospital，Southern Medical University from January 2024 to January 2025，were collected for retrospective analysis，with each patient having 1 to 3 dentures in the mouth. CBCT images with beam hardening artifacts，which were reconstructed using an iterative reconstruction algorithm and underwent no additional processing，were recorded as the pre-correction group；the CBCT images reconstructed via the same iterative reconstruction algorithm and further subjected to artifact correction using the Reduce Scatter module of Mimics software were recorded as the post-correction group. The buccal soft tissue unaffected by denture artifacts was used as the control，and the contrast-to-noise ratio（CNR）and artifact index（AI）of the lip soft tissue，tongue tissue，and artifact area in the same CBCT slice images of the two groups were calculated and compared. Two attending radiologists independently completed the subjective scoring of the two groups of images using a 5-point scale through a double-blind method，and the consistency of the subjective scoring results between the two attending radiologists and the differences in subjective scores between the two groups of images were analyzed. Results    Among the 65 patients，30 cases（accounting for 46.15%）had 1 denture in the mouth，20 cases（accounting for 30.77%）had 2 dentures，and 15 cases（accounting for 23.08%）had 3 dentures. The Kappa values of the subjective scores given by the two attending radiologists for different parts of the CBCT images were all > 0.40，indicating a moderate level of consistency. Comparing the images with the same number of intraoral dentures in the lip soft tissue，tongue tissue，and artifact area，the post-correction group showed a decrease in AI，an increase in CNR，and an increase in subjective scores compared with the pre-correction group. All these differences were statistically significant （all P < 0.05）. Conclusion    Mimics software can effectively reduce the beam hardening artifacts caused by 1 to 3 intraoral dentures in CBCT images，improve image quality，and help clinicians observe the intraoral anatomical structures in detail.

Key words: cone beam CT, hardening artifacts, Mimics, artifact index, contrast-to-noise ratio