锥形束CT与8层螺旋CT检测牙根外吸收的可靠性  

Diagnostic accuracy of cone beam computed tomography and eight-slice computed tomography for evaluation of external root reabsorption

作　　者：谢晓艳[1] 张祖燕[1] 

机构地区：[1]北京大学口腔医学院·口腔医院放射科,北京100081

出　　处：《北京大学学报（医学版）》2012年第4期628-632,共5页Journal of Peking University:Health Sciences

摘　　要：目的:在体外条件下比较锥形束CT(cone beam computed tomography,CBCT)和多层螺旋CT(multi-slicecomputed tomography,MSCT)检测牙根外吸收的可靠性,评估CBCT诊断牙根表面微小缺损的能力,并探讨其三维影像学特点。方法:在40颗离体单根牙舌面的根颈、根中和根尖部随机制备洞型,直径为1 mm,深度分别为0.1 mm、0.2 mm、0.3 mm、0.4 mm,用以模拟牙根外吸收缺损。分别对样本进行容积扫描(日本森田株式会社生产Accuito-mo 3DX型CBCT)和层厚0.625 mm的高分辨薄层扫描(美国GE公司生产BrightSpeed Edge型8层MSCT);两名研究者评估图像,进行受试者工作特征(receiver operating characteristics,ROC)曲线分析,得到曲线下面积(Az值),用于评估两种设备检测牙根外吸收的可靠性。结果:CBCT和MSCT检测所有部位、所有大小缺损的Az值分别为0.921和0.770;检测根颈部缺损的Az值分别为0.885和0.752,根中部缺损的Az值分别为0.991和0.844,根尖部缺损的Az值分别为0.873和0.709;检测0.1 mm缺损的Az值分别为0.794和0.592,0.2 mm缺损的Az值分别为0.934和0.719,0.3 mm缺损的Az值分别是0.992和0.920,0.4 mm缺损的Az值分别为0.992和0.990。结论:体外条件下,Accuitomo 3DX型CBCT检测单根牙根舌面缺损的可靠性优于8层MSCT,检测小缺损的优势更明显;CBCT对深度大于0.2 mm缺损的检测能力明显优于深度0.1 mm的缺损,MSCT对深度大于0.3 mm缺损的检测能力明显优于深度小于0.2 mm的缺损;两种设备检测根中部缺损的可靠性均高于根颈部和根尖部。Objective： To evaluate the diagnostic accuracy of cone beam computed tomography （CBCT） and high resolution multi-slice computed tomography （MSCT） with eight-detector-rows in detecting the simulated external root resorption defects. Methods： External root resorption defects of different sizes and in different locations were simulated in 40 human single rooted teeth. Cavities simulating root resorption defects of 1 mm in diameter and 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm in depth were drilled in the cervical, middle and apical thirds of lingual surfaces of the teeth. The specimens were scanned with both CBCT （Accuitomo 3DX, Morita Co. , Japan） and high resolution 8-slice CT （BrightSpeed Edge, GE Co. , USA）. The CBCT and MSCT images were read by two experienced observers. The data were analyzed with receiver operating characteristics （ROC） analysis. ROC curves were generated and the are- a under ROC curve （Az） was employed to express the diagnostic accuracy. Results： The diagnostic accuracy （Az value） in detecting the simulated defects of all the locations and sizes were 0. 921 for CBCT and 0.770 for MSCT. The Az values for CBCT in detecting defects located in the cervical, middle and apical thirds were 0. 885, 0. 991 and 0. 873, while those for MSCT were 0. 752, 0. 844 and 0. 709, respectively. The Az values for CBCT in detecting the defects of 0.1 mm, 0.2 mm, 0.3 mm and 0.4 mm in depth were 0. 794, 0. 934, 0.992 and 0. 992, and those for MSCT were 0. 592, 0. 719, 0. 920 and 0. 990, respectively. Conclusion： The diagnostic ability for external root resorption of CBCT is better than that of MSCT. Smaller defects are better delineated with CBCT than with MSCT. The defects in the middle thirds of the roots are easier to be detected than those in the cervical and apical ones using both CBCT and MSCT.

关 键 词：牙根吸收 锥形束计算机体层摄影术 体层摄影术 螺旋计算机 

分 类 号：R781.34[医药卫生—口腔医学]