OBJECTIVE. The purpose of this article is to assess the "reversed halo" sign in patients with septic pulmonary embolism (PE) due to IV substance use disorder. MATERIALS AND METHODS. A retrospective analysis was performed of chest CT scans obtained between 2007 and 2017 that had findings of septic PE associated with IV substance use disorder. Inclusion criteria were history of IV substance use disorder, findings of septic PE on chest CT scans, and confirmation of infection. Image analysis was performed by three radiologists to assess the frequency, appearance, and evolution of the reversed halo sign. Interreader agreement to characterize the reversed halo sign was assessed using kappa statistical analysis. The chi-square test was used to correlate reversed halo sign shape with evolution on follow-up scans. RESULTS. Of 62 patients who met the inclusion criteria (54.8% women; mean age, 32.8 ± 8.3 [SD] years), 59.7% (37/62) had reversed halo signs (κ = 0.837-0.958, p < 0.0001). The mean number of unique reversed halo signs per patient was 2.1 ± 1.7 (46.7% of patients had more than one reversed halo sign). Of 78 unique reversed halo signs, 93.6% (73/78) were peripherally located and 51.3% (40/78) were located at the lower lobe, 52.6% (41/78) were pyramidal and 47.4% (37/78) were round shaped, 89.7% (70/78) had central low-attenuation areas, and 34.6% (27/78) had internal reticulations. Cavitation developed in 37.2% (29/78) of reversed halo signs and more often in pyramid-shaped ones (70.8%, 17/24), whereas consolidation occurred in 30.8% (24/78) and more often in round-shaped ones (58.6%; 17/29, p = 0.03). CONCLUSION. Septic PE should be considered in the differential diagnosis of patients with IV substance use disorder presenting with reversed halo sign. The reversed halo sign was reliably and frequently observed on the chest CT scans of patients with IV substance use disorder-related septic PE. Characteristics of reversed halo sign presentation were identified as potential features to differentiate septic PE from other causes of pulmonary infarct manifesting with reversed halo sign.

中文翻译：

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由于IV物质使用障碍导致败血症性肺栓塞的患者出现晕轮症状的频率和可靠性。

目的。本文的目的是评估由于IV物质使用障碍而导致的败血性肺栓塞（PE）患者的“反向光晕”征象。材料和方法。回顾性分析了2007年至2017年期间获得的胸部CT扫描结果，发现了与IV物质使用障碍相关的脓毒性PE。入选标准为IV物质使用障碍史，胸部CT扫描中发现的败血性PE和感染确认。由三名放射科医生进行了图像分析，以评估反转光晕征兆的频率，外观和演变。使用kappa统计分析评估了阅读器之间的一致性，以表征反向的光晕迹象。卡方检验用于在后续扫描中将反转的光环符号形状与演变相关联。结果。在符合纳入标准的62例患者中（54.8％的女性；平均年龄32.8±8.3 [SD]岁），有59.7％（37/62）的光晕迹象反转（κ= 0.837-0.958，p <0.0001）。每位患者的独特逆向晕征平均数为2.1±1.7（46.7％的患者具有多个逆向晕征）。在78个独特的反向光晕征兆中，位于外围的93.6％（73/78）和位于下部下叶的51.3％（40/78），呈锥体的52.6％（41/78）和47.4％（37/78）圆形，有89.7％（70/78）有中央低衰减区域，有34.6％（27/78）有内部网状结构。空化现象在反向晕轮征兆中占37.2％（29/78），而金字塔形的则较常见（70.8％，17/24），而固结化的比率为30.8％（24/78），圆形的则更为常见（58.6％； 17/29，p = 0.03）。结论。在对IV物质使用障碍表现出反向晕征的患者进行鉴别诊断时，应考虑使用败血性PE。在与IV物质使用障碍相关的脓毒性PE的患者的胸部CT扫描中，可靠且经常观察到反转的晕轮征兆。反向晕轮征象表现的特征被鉴定为将败血症性PE与其他由反向晕轮征象引起的肺梗死原因区分开的潜在特征。