Silva Alexandre Tejo Pereira de Brito, Silva Lucas Tejo Pereira de Brito, Vieira Alysson Emannuel Neves Rodrigues, de Melo Cibelle Ingrid Estevão, do Nascimento José Jailson Costa, de Mello Júnior Carlos Fernando, Vasconcelos Selene Cordeiro, de Araújo-Neto Severino Aires
Universidade Federal da Paraíba (UFPB), João Pessoa, PB, Brazil.
Universidade Federal de Pernambuco (UFPE), Recife, PE, Brazil.
Radiol Bras. 2020 Sep-Oct;53(5):314-319. doi: 10.1590/0100-3984.2019.0068.
The present study aims to perform a reproducibility study of the clivus-canal angle (CCA), Welcker's basal angle (WBA), and the distance from the odontoid process to Chamberlain's line (DOCL) on magnetic resonance imaging (MRI).
Two medical students and two radiologists respectively evaluated 100 and 50 consecutive MRI scans of adult skulls, selected randomly. Each examiner, working independently and blinded to the previous results, performed readings for each patient on two different occasions. Measurements were performed in T1-weighted sequences acquired in the midsagittal plane. The levels of intraobserver reproducibility and interobserver agreement were evaluated by calculating the intraclass correlation coefficients (ICCs) and the corresponding 95% confidence intervals.
The mean values obtained by the examiners were 150º for the CCA, 130º for the WBA, and 2.5 mm for the DOCL. The ICC for interobserver agreement was 0.980, 0.935, and 0.967, for the CCA, WBA, and DOCL, respectively, for the students, compared with 0.977, 0.941, and 0.982, respectively, for the radiologists, and 0.980, 0.992, and 0.990, respectively, for all of the examiners together. In the analysis of intraobserver agreement, the ICC ranged from 0.929 to 0.959 for the CCA, from 0.918 to 0.964 for the WBA, and from 0.918 to 0.981 for the DOCL.
The measurement of the CCA, WBA, and DOCL appears to show excellent intraobserver reproducibility and interobserver agreement on MRI.
本研究旨在对磁共振成像（MRI）上的斜坡-椎管角（CCA）、韦尔克基底角（WBA）以及齿突至钱伯林线的距离（DOCL）进行重复性研究。
两名医学生和两名放射科医生分别对随机选取的100例和50例成人颅骨的连续MRI扫描进行评估。每位检查者独立工作，对先前结果不知情，在两个不同时间对每位患者进行读数。测量在矢状面获取的T1加权序列中进行。通过计算组内相关系数（ICC）及其相应的95%置信区间来评估观察者内重复性水平和观察者间一致性。
检查者获得的CCA平均值为150°，WBA为130°，DOCL为2.5mm。对于医学生，CCA、WBA和DOCL的观察者间一致性ICC分别为0.980、0.935和0.967，放射科医生分别为0.977、0.941和0.982，所有检查者一起分别为0.980、0.992和0.990。在观察者内一致性分析中，CCA的ICC范围为0.929至0.959，WBA为0.918至0.964，DOCL为0.918至0.981。
在MRI上，CCA、WBA和DOCL的测量显示出优异的观察者内重复性和观察者间一致性。
