Nikbin Ava, Dalili Kajan Zahra, Taramsari Mehran, Khosravifard Negar
Department of Maxillofacial Radiology, Faculty of Dentistry, Guilan University of Medical Sciences, Rasht, Iran.
Dental Sciences Research Center, Department of Maxillofacial Radiology, Faculty of Dentistry, Guilan University of Medical Sciences, Rasht, Iran.
Imaging Sci Dent. 2018 Dec;48(4):245-254. doi: 10.5624/isd.2018.48.4.245. Epub 2018 Dec 20.
To assess the effects of object position in the field of view (FOV) and application of a metal artifact reduction (MAR) algorithm on the diagnostic accuracy of cone-beam computed tomography (CBCT) for the detection of vertical root fractures (VRFs).
Sixty human single-canal premolars received root canal treatment. VRFs were induced in 30 endodontically treated teeth. The teeth were then divided into 4 groups, with 2 groups receiving metal posts and the remaining 2 only having an empty post space. The roots from different groups were mounted in a phantom made of cow rib bone, and CBCT scans were obtained for the 4 different groups. Three observers evaluated the images independently.
The highest frequency of correct diagnoses of VRFs was obtained with the object positioned centrally in the FOV, using the MAR algorithm. Peripheral positioning of the object without the MAR algorithm yielded the highest sensitivity for the first observer (66.7%). For the second and third observers, a central position improved sensitivity, with or without the MAR algorithm. In the presence of metal posts, central positioning of the object in the FOV significantly increased the diagnostic sensitivity and accuracy compared to peripheral positioning.
Diagnostic accuracy was higher with central positioning than with peripheral positioning, irrespective of whether the MAR algorithm was applied. However, the effect of the MAR algorithm was more significant with central positioning than with peripheral positioning of the object in the FOV. The clinical experience and expertise of the observers may serve as a confounder in this respect.
评估视野(FOV)中物体位置以及金属伪影减少(MAR)算法的应用对锥束计算机断层扫描(CBCT)检测垂直根折(VRF)诊断准确性的影响。
60颗人类单根管前磨牙接受根管治疗。在30颗经牙髓治疗的牙齿中诱导产生垂直根折。然后将牙齿分为4组,其中2组植入金属桩,其余2组仅留空桩腔。将不同组的牙根安装在由牛肋骨制成的模型中,对4组分别进行CBCT扫描。三名观察者独立评估图像。
使用MAR算法且物体位于FOV中心时,对VRF的正确诊断频率最高。对于第一位观察者,物体位于外周且未使用MAR算法时灵敏度最高(66.7%)。对于第二位和第三位观察者,无论是否使用MAR算法,物体位于中心位置时灵敏度均有所提高。存在金属桩时,与外周位置相比,物体位于FOV中心位置可显著提高诊断灵敏度和准确性。
无论是否应用MAR算法,中心位置的诊断准确性均高于外周位置。然而,MAR算法在物体位于FOV中心位置时的效果比在外周位置时更显著。观察者的临床经验和专业知识在这方面可能是一个混杂因素。