Fakhar Hooriyeh Bashizade, Emami Raheleh, Moloudi Kave, Mosavat Farzaneh
Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Semnan University of Medical Sciences, Semnan, Iran.
Dent Res J (Isfahan). 2018 Mar-Apr;15(2):89-94.
Dental implants and metal fillings may cause artifacts in cone-beam computed tomography (CBCT) images and reduce image quality and anatomic accuracy. The purposes of this study are a subjective evaluation of anatomic landmarks and linear bone measurements after applying artifact removal (low-medium) option on CBCT images.
In this cross-sectional study, thirty CBCT images from thirty qualified patients were selected in a private radiology center. Low and medium artifact removal was applied to images. Three radiologists assessed the visibility of the mandibular canal, mental foramen, and lamina dura in images. Crestal width and bone length were also measured in three groups of images and was compared by exact McNemar test. ICC test (two-way random model, absolute agreement types) was calculated for comparison of linear bone measurements in three images groups. ≤ 0.05 was considered statistically significant.
Percent agreement of determining mental foramen (outline and location), mandibular canal (outline and location), and lamina dura between three groups of images were 100%, 100%, 83.3%, 96.7%, and 56.6%, respectively. The results of exact McNemar test revealed that medium artifact removal group had a statistical difference in lamina dura observation with none and low artifact removal groups ( < 0.001). Intraclass correlation coefficient showed no statistical differences in crestal width and bone length between groups ( < 0.001).
Applying artifact removal does not affect the visibility of large anatomical structures and linear bone measurements, but delicate structures such as lamina dura may become less clear after artifact removal.
牙种植体和金属填充物可能会在锥形束计算机断层扫描（CBCT）图像中产生伪影，降低图像质量和解剖学准确性。本研究的目的是对CBCT图像应用伪影去除（低-中）选项后，对解剖标志和线性骨测量进行主观评估。
在这项横断面研究中，在一家私立放射中心选取了30例合格患者的30张CBCT图像。对图像应用低和中伪影去除。三名放射科医生评估图像中下颌管、颏孔和硬骨板的可视性。还在三组图像中测量了嵴顶宽度和骨长度，并通过精确的麦克尼马尔检验进行比较。计算组内相关系数（ICC检验，双向随机模型，绝对一致性类型）以比较三组图像中的线性骨测量。P≤0.05被认为具有统计学意义。
三组图像之间确定颏孔（轮廓和位置）、下颌管（轮廓和位置）和硬骨板的一致率分别为100%、100%、83.3%、96.7%和56.6%。精确麦克尼马尔检验结果显示，中伪影去除组在硬骨板观察方面与无伪影去除组和低伪影去除组存在统计学差异（P<0.001）。组内相关系数显示，各组之间的嵴顶宽度和骨长度无统计学差异（P<0.001）。
应用伪影去除不影响大型解剖结构的可视性和线性骨测量，但硬骨板等精细结构在伪影去除后可能会变得不那么清晰。
