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行业新闻:用低剂量CT进行COVID-19评估的效果很好

2020-04-26 09:58:46  来源:




据AuntMinnie.com报道, 2020年4月21日发表于Radiology: Cardiothoracic Imaging 一篇论文发现[1],剂量在1mSv以下(亚mSv)的胸部CT可以准确快速地评估急诊室患者的COVID-19感染情况,特别是那些出现症状超过48小时的病人。这能够帮助临床医生快速诊断病人,同时避免不必要的辐射。鉴于目前胸部CT在COVID-19检测中应用广泛,亚mSv胸部CT照射剂量小(比Tao等人[2] 使用的CT减少到1/5),使用亚mSv胸部CT可以大幅度减少人群接受剂量。


Dangis团队指出,实时聚合酶链反应(RT-PCR)测试是现在诊断COVID-19的黄金标准,但是它的灵敏度可低至70%。而一些研究证明,胸部CT的灵敏度可超过90%,提供了诊断新冠肺炎的另一种工具。

为了确定剂量大小和诊断CT所需时间,Dangis的团队对192名具有COVID-19症状的急诊室患者进行研究。这些患者在3月14至24日期间接受了亚mSv胸部CT照射以及RT-PCR测试,CT照射参数为100kVp、20mAs、螺距1.2,治疗床旋转0.5秒。在192名病人中,43.2%的人COVID-19检测呈阳性,其余56.8%的人检测呈阴性。病人的平均年龄是62岁,但患有COVID-19的人平均年龄(67岁)高于不患病的人(57岁),并且有更大概率出现发热(68.7%和45.9%)。


小组发现亚mSv胸部CT在各种测量数据中表现良好,特别是对出现症状超过48小时的病例(图1、表1)。亚mSv胸部CT的平均有效剂量是0.56mSv。获取CT图像和患者报告的中位时间是25分钟(13-49分钟)。CT测试中观察者内相关系数和观察者间相关系数分别是0.96和0.95,没有明显偏差。



图1 两个患有COVID-19的病例的CT图像。图A和图B是一位呼吸困难、发烧的85岁女士的轴向(A)和冠向(B)CT图像。CT图像显示了典型的早期COVID-19症状,双侧胸膜下出现磨玻璃影(箭头所示)。有效剂量是0.52mSv。图C和图D是一位咳嗽、发烧14天的41岁女士的轴向(C)和冠向(D)CT图像。CT图像显示了典型的COVID-19晚期症状,双侧胸膜下出现多灶性实变(箭头所示)。有效剂量是0.53mSv。上述图片和标题由北美放射学会(Radiological Society of North America, RSNA)提供。


因此Dangis总结认为,对可能感染COVID-19的患者进行早期诊断分类时,低剂量亚mSv胸部CT可以作为RT-PCR重要的补充手段


[1] Anthony Dangis, Christopher Gieraerts, Yves De Bruecker, Lode Janssen, Hanne Valgaeren, Dagmar Obbels, Marc Gillis, Marc Van Ranst, Johan Frans, Annick Demeyere, Rolf Symons. Accuracy and reproducibility of low-dose submillisievert chest CT for the diagnosis of COVID-19. Radiology. Vol.2. No. 2 (Apr 21 2020) https://doi.org/10.1148/ryct.2020200196. 

[2] Ai, T., Yang, Z., Hou, H., Zhan, C., Chen, C., Lv, W., ... & Xia, L. (2020). Correlation of Chest CT and RT-PCR Testing in Coronavirus Disease 2019 (COVID-19) in China: A Report of 1014 C


 

以下为原文:

Low-dose CT works well for COVID-19 assessment


Chest CT at a radiation dose under 1 mSv can accurately and rapidly assess COVID-19 infection in emergency room patients -- particularly those who have had symptoms longer than 48 hours, according to a study published April 21 in Radiology: Cardiothoracic Imaging by Dangis et al [1].

The results are good news for clinicians seeking to diagnose patients quickly while also avoiding undue radiation exposure, wrote a team led by Dr. Anthony Dangis of Imelda Hospital in Bonheiden, Belgium.

"[We found] an estimated radiation dose reduction by a factor of five," the group wrote. "Given the widespread use of chest CT for COVID-19 detection, our results demonstrate the feasibility of using low-dose chest CT to achieve an important reduction in radiation dose on a population level during this pandemic."

Real time polymerase chain reaction (RT-PCR) testing is currently the gold standard for diagnosing COVID-19, but its sensitivity can be as low as 70%, the group noted. Chest CT offers an additional diagnostic tool for the disease, with a sensitivity of more than 90%, according to some studies.