105例新型冠状病毒肺炎胸部CT影像学特征——山东省多中心回顾性分析

Chest CT features of 105 patients with COVID-19: a multicenter retrospective study in Shandong Province

目的通过山东省多中心研究探讨新型冠状病毒肺炎(COVID-19)胸部CT影像特征及其临床应用价值。方法回顾性分析2020年1至3月按照《新型冠状病毒肺炎诊疗方案(试行第6版)》经核酸检测确诊并治愈出院(或死亡)共计105例COVID-19患者的流行病学、临床以及胸部CT影像资料。其中普通型患者(普通组)92例,重型或危重型患者(重症组)13例。对胸部CT影像学基本特征及动态演变特征进行统计分析;并将普通组与重症组进行对照分析。结果所有患者均有明确流行病学史。初期临床症状主要为不明原因发热(85%,90/105)、咳嗽、咳痰(72%,75/105)。实验室检查异常表现为白细胞计数减低(11%,12/105)及淋巴细胞计数减低(38%,40/105)。胸部CT基本征象分析结果显示,早期双肺呈多发磨玻璃病变(GGO)(98%),平均受累肺叶3个(2,5),主要分布于肺中、外带胸膜下;进展期大部分GGO实变(96%)、伴小叶间隔增厚(64%),部分呈铺路石征(42%),反应性胸膜增厚(23%),胸腔积液(3例),气胸(1例);恢复期显示纤维条纹征(49%)。另一重要特点为双肺外带表现明显的空气-细支气管征(41%)和微血管扩张征(40%)。普通组与重症组对比结果显示,重症组受累肺叶数目多于普通组(P<0.001);重症组受累半定量积分高于普通组(P<0.001)。重症组铺路石征(85%vs 34%,P=0.001)、小叶间隔增厚(92%vs 61%,P=0.029)及胸膜增厚(69%vs 16%,P<0.001)、纤维条纹征(85%vs 43%,P=0.007)相比更高。胸部CT动态影像分析结果显示,疾病初始阳性影像表现迟于临床症状,肺部CT 5 d(5, 6)开始呈阳性,CT病变进展时间5 d(5, 7),持续进展至11 d(10, 14)即CT病变峰值时间,CT病变转归时间12 d(11, 15)。病灶进展与转归时间的长短与疾病严重程度相关,核酸检测阴性后影像转归滞后。结论 COVID-19胸部CT具有一定的特异性表现,主要为典型磨玻璃病变及其特征性动态演变,以及空气-细支气管征和微血管扩张征表现,结合半定量评估,可以为COVID-19早期诊断、临床分型及预后评估提供可靠依据。

Objective To explore the chest CT features of patients with coronavirus disease 19(COVID-19) and the clinical application value. Methods The epidemiological, clinical and chest CT data of 105 COVID-19 cases confirmed by nucleic acid test in accordance with Diagnosis and Treatment of Novel Coronavirus Pneumonia(trial version sixth) who were treated and cured(or died) during Jan. and Mar. 2020 were retrospectively analyzed. The patients included 92 common cases and 13 severe or critical cases, averaged 48±14(21-88) years old. The basic and dynamic characteristics of chest CT images were analyzed and compared between the two groups. Results All patients had a clear epidemiological history. The main initial clinical symptoms were fever(85%, 90/105), cough and expectoration(72%, 75/105). Both leucocyte count(11%, 12/105) and lymphocyte count(38%, 40/105) were decreased. Chest CT showed that in the early stage, multiple ground glass opacity(GGO, 98%) was observed in bilateral lungs involving 3 lobes(2, 5) in average, mainly distributed in the middle and outer zone of the lung under pleura;in the progressive stage, GGO consolidated(96%), with interlobular septal thickening(64%), paving stone sign(42%), reactive pleura thickening(23%), pleural effusion(3 cases), pneumothorax(1 case);in the recovery stage, fibrous streak sign was observed(49%). Another important feature was typical air bronchogram sign(ABS, 41%) and microvascular dilation sign(MVDS, 40%) in the extrapulmonary zone. Compared with the common cases, the severe cases had more lobes involved(P<0.001), higher semi-quantitative score(P<0.001), and higher incidences of paving stone sign(85% vs 34%, P=0.001), interlobular septal thickening(92% vs 61%, P=0.029), pleural thickening(69% vs 16%, P<0.001), and fibrous streak sign(85% vs 43%, P=0.007). Dynamic image analysis showed that in the initial stage, positive image manifested later than clinical symptoms: chest CT showed positive signs of the disease on day 5(5, 6), the disease progressed on day 5(5, 7) until day 11(10, 14), and showed possible outcome after another 12(11, 15) days. The span between progression and outcome was related to the severity of disease, and CT outcome was delayed after nucleic acid test was negative. Conclusion COVID-19 shows some specific manifestations on chest CT, characterized by GGO, dynamic evolution, ABS and MVDS. The above manifestations and semi-quantitative evaluation can provide reliable basis for the early diagnosis, clinical classification and prognosis evaluation of COVID-19.