Department of Clinical Radiology, Great Ormond Street Hospital for Children, London, UK; UCL Great Ormond Street Institute of Child Health, London, UK.
UCL Great Ormond Street Institute of Child Health, London, UK; Centre of Applied Statistics Courses, University College London, London, UK.
Lancet Child Adolesc Health. 2018 Nov;2(11):802-811. doi: 10.1016/S2352-4642(18)30274-8. Epub 2018 Sep 22.
Internationally, chest radiography is the standard investigation for identifying rib fractures in suspected physical abuse in infants. Several small observation studies in children have found that chest CT can provide greater accuracy than radiography for fracture detection, potentially aiding medicolegal proceedings in abuse cases; however, to our knowledge, this greater accuracy has not been comprehensively evaluated. We aimed to determine differences in rib fracture detection rates between post-mortem chest radiographs and chest CT images, using forensic autopsy as the reference standard.
In this retrospective diagnostic accuracy study, we searched the Great Ormond Street Hospital (London, UK) radiology information system for all children aged 0-16 years who had a post-mortem skeletal survey (ie, full-body radiography), CT, and full autopsy between Jan 1, 2012, and Jan 1, 2017, for a purpose of death investigation. Cases were excluded if the imaging was done for a reason other than a forensic investigation or if image quality was suboptimal. Radiologists were recruited as reporters on a voluntary basis via membership databases from international radiology and post-mortem imaging societies with no specific inclusion or exclusion criteria. Reporters were sent a set of chest radiographs on a password protected and encrypted USB flash drive or via a secure filesharing website and independently reported on the presence of rib fractures, fracture location, and the confidence level of their interpretation. They were masked to the clinical information of the images. 1 month later, the same reporters were sent CTs for the same cases in a random order and asked to report on the same features. The primary objective was to compare the accuracy of detection of rib fractures by use of post-mortem chest radiographs and CTs, with autopsy data as reference standard. Accuracy was assessed by comparison of diagnostic statistics, calculated using random-intercept multilevel logistic models with reporter and patient included as cross-classified random-effects.
25 cases of children (aged 1 month to 7 years), with 136 rib fractures at autopsy with paired post-mortem chest radiographs and CTs, were selected for analysis. 38 radiologists were recruited as reporters from 23 international centres; 12 (32%) were consultants, median experience of 14·5 years (range 6-27), and 26 (68%) were registrars, median experience of 4 years (range 2-9). Across all radiologists, three times as many rib fractures were correctly detected by use of chest CTs compared with chest radiography (sensitivity 44·9% [95% CI 31·7-58·9] vs 13·5% [8·1-21·5]; difference 31·4% [23·3-37·8; p<0·001]). Sensitivity for detection on the correct rib was higher by use of CT than by use of radiography (62·4% [95% CI 44·9-77·1] vs 23·1% [12·9-37·8]; difference 39·3% [31·9-42·2; p<0·001]), as was diagnosis of a patient with any rib fracture or fractures (81·5% [75·8-86·0] vs 64·7% [57·3-71·4]; difference 16·7% [11·5-22·2; p<0·001]). Radiologist confidence was higher when using CT images than radiographs (highest confidence rating given on 3317 [63·6%] of 5218 fractures for CT vs 1518 [46·6%] of 3303 on radiographs) and was a predictor for accurate fracture detection.
Chest CT provides greater accuracy than conventional chest radiography for post-mortem rib fracture detection, irrespective of radiologist experience or fracture location, although both methods detected a substantial number of false positives. The diagnostic accuracy of CT should be studied further in live children ideally in a multicentre trial to assess the applicability of our results.
Great Ormond Street Children's Charity, Medical Research Council, Royal College of Radiologists, Research Councils UK, National Institute for Health Research.
在国际上，胸部 X 射线摄影是疑似身体虐待的婴儿中识别肋骨骨折的标准检查方法。一些针对儿童的小型观察性研究发现，胸部 CT 比 X 射线摄影在骨折检测方面具有更高的准确性，这可能有助于虐待案件的法医诉讼；然而，据我们所知，这种更高的准确性尚未得到全面评估。我们旨在确定死后胸部 X 射线摄影和胸部 CT 图像在肋骨骨折检测率方面的差异，以法医解剖作为参考标准。
在这项回顾性诊断准确性研究中，我们通过大奥蒙德街医院（伦敦，英国）放射信息系统搜索了 2012 年 1 月 1 日至 2017 年 1 月 1 日期间因死因调查进行过全身骨骼 X 射线摄影（即全身 X 射线摄影）、CT 和全尸检的 0-16 岁儿童的所有病例。如果成像的目的不是法医调查，或者图像质量不佳，则排除病例。通过国际放射学和死后成像协会的成员数据库招募放射科医生作为自愿报告员，没有具体的纳入或排除标准。报告员收到一套胸部 X 射线照片，放在受密码保护和加密的 USB 闪存驱动器上，或通过安全文件共享网站发送，并独立报告肋骨骨折的存在、骨折位置以及他们解释的置信水平。他们对图像的临床信息进行了屏蔽。一个月后，以随机顺序向同一批报告员发送相同病例的 CT，并要求他们报告相同的特征。主要目的是比较使用死后胸部 X 射线摄影和 CT 的肋骨骨折检测准确性，以尸检数据作为参考标准。准确性通过使用随机截距多水平逻辑模型进行比较，使用报告员和患者作为交叉分类随机效应进行评估。
选择了 25 例年龄在 1 个月至 7 岁的儿童，共 136 处肋骨骨折，进行尸检，并与死后胸部 X 射线摄影和 CT 配对。从 23 个国际中心招募了 38 名放射科医生作为报告员；12 名（32%）为顾问，中位经验为 14.5 年（范围 6-27），26 名（68%）为住院医师，中位经验为 4 年（范围 2-9）。在所有放射科医生中，使用胸部 CT 检测肋骨骨折的正确检测率是胸部 X 射线摄影的三倍（敏感性 44.9%[95%CI 31.7-58.9] vs 13.5%[8.1-21.5]；差异 31.4%[23.3-37.8；p<0.001]）。使用 CT 检测正确肋骨骨折的敏感性高于使用 X 射线摄影（62.4%[44.9-77.1] vs 23.1%[12.9-37.8]；差异 39.3%[31.9-42.2；p<0.001]），以及诊断任何肋骨骨折或骨折的患者的敏感性（81.5%[75.8-86.0] vs 64.7%[57.3-71.4]；差异 16.7%[11.5-22.2；p<0.001]）。与 X 射线摄影相比，放射科医生使用 CT 图像时的信心更高（在 CT 上，3317 处骨折中有 63.6%[5218 处]被评为最高信心评分，而在 X 射线摄影上，3303 处骨折中有 1518 处[46.6%]），并且是准确骨折检测的预测因素。
与传统的胸部 X 射线摄影相比，胸部 CT 为死后肋骨骨折检测提供了更高的准确性，无论放射科医生的经验或骨折位置如何，尽管两种方法都检测到了大量的假阳性。应在理想情况下在多中心试验中进一步研究 CT 的诊断准确性，以评估我们结果的适用性。
大奥蒙德街儿童慈善基金会、医学研究理事会、皇家放射科医师学院、英国研究理事会、国家健康研究所。
