Background RSNA consensus guidelines for COVID-19-related chest CT are widely used but, to the knowledge of the authors, their rate of true-positive findings for COVID-19 pneumonia in vaccinated patients has not been assessed. Purpose To assess the rate of true-positive findings of typical appearance for COVID-19 at chest CT by using RSNA guidelines in fully vaccinated patients with polymerase chain reaction (PCR)-confirmed COVID-19 infection compared with unvaccinated patients. Materials and Methods Included were patients with COVID-19 who had typical appearance on chest CT images and one PCR test for COVID-19 with a positive result or two tests with negative results within 7 days of undergoing chest CT between January 2021 and January 2022 at a quaternary academic medical center. True-positive findings were defined as chest CT images interpreted as COVID-19 typical appearance and PCR-confirmed COVID-19 infection within 7 days. Logistic regression models were constructed to quantify the association between PCR results and vaccination status, vaccination status and COVID-19 variants, and vaccination status and number of months. Results Included were 652 patients (median age, 59 years; IQR, 48-72 years; 371 men [57%]) with CT scans classified as typical appearance. Of those patients, 483 (74%) were unvaccinated and 169 (26%) were fully vaccinated. The overall rate of true-positive findings on CT images rated as typical appearance was lower in vaccinated versus unvaccinated patients (70 of 169 [41%; 95% CI: 34, 49] vs 352 of 483 [73%; 95% CI: 69, 77]; odds ratio [OR], 3.8 [95% CI: 2.6, 5.5]; P < .001). Unvaccinated patients were more likely to have true-positive findings on CT images compared with fully vaccinated patients during the peaks of COVID-19 variants Alpha (OR, 16; 95% CI: 6, 42; P < .001) and Delta (OR, 8; 95% CI: 4, 16; P < .001), but no statistical differences were found during the peak of the Omicron variant (OR, 1.7; 95% CI: 0.3, 11; P = .56). Conclusion Fully vaccinated patients with confirmed COVID-19 breakthrough infections had lower rates of true-positive findings of COVID-19 typical appearance at chest CT. © RSNA, 2022 Supplemental material is available for this article.

中文翻译：

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根据 RSNA 共识指南，在越来越多的疫苗接种人群中，胸部 CT 上 COVID-19 典型表现的真阳性发现率。

背景 RSNA 与 COVID-19 相关的胸部 CT 共识指南被广泛使用，但据作者所知，他们尚未评估接种疫苗的患者中 COVID-19 肺炎的真阳性发现率。目的 与未接种疫苗的患者相比，使用 RSNA 指南评估完全接种疫苗的聚合酶链反应 (PCR) 确诊 COVID-19 感染患者在胸部 CT 上 COVID-19 典型表现的真阳性发现率。材料和方法 包括在 2021 年 1 月至 2022 年 1 月期间接受胸部 CT 后 7 天内在胸部 CT 图像上具有典型外观的 COVID-19 患者和一次 COVID-19 PCR 检测呈阳性结果或两次检测呈阴性结果第四纪学术医学中心 真阳性结果定义为 7 天内胸部 CT 图像被解释为 COVID-19 典型表现和 PCR 确认的 COVID-19 感染。构建逻辑回归模型以量化 PCR 结果与疫苗接种状态、疫苗接种状态和 COVID-19 变体以及疫苗接种状态和月数之间的关联。结果 包括 652 名患者（中位年龄，59 岁；IQR，48-72 岁；371 名男性 [57%]），其 CT 扫描被归类为典型外观。在这些患者中，483 名 (74%) 未接种疫苗，169 名 (26%) 已完全接种疫苗。接种疫苗的患者与未接种疫苗的患者相比，在 CT 图像上被评为典型外观的真阳性发现的总体比率较低（169 名患者中的 70 名 [41%；95% CI：34、49] vs 483 名患者中的 352 名 [73%；95% CI： 69、77]；比值比 [OR]，3.8 [95% CI：2.6、5.5]；P < .001）。与完全接种疫苗的患者相比，未接种疫苗的患者在 COVID-19 变体 Alpha（OR，16；95% CI：6、42；P <.001）和 Delta（OR , 8; 95% CI: 4, 16; P < .001)，但在 Omicron 变体的峰值期间未发现统计学差异（OR, 1.7; 95% CI: 0.3, 11; P = .56）。结论 已确诊 COVID-19 突破性感染且完全接种疫苗的患者在胸部 CT 上 COVID-19 典型表现的真阳性发现率较低。© RSNA，2022 补充材料可用于本文。但在 Omicron 变体的峰值期间未发现统计学差异（OR，1.7；95% CI：0.3、11；P = .56）。结论 已确诊 COVID-19 突破性感染且完全接种疫苗的患者在胸部 CT 上 COVID-19 典型表现的真阳性发现率较低。© RSNA，2022 补充材料可用于本文。但在 Omicron 变体的峰值期间未发现统计学差异（OR，1.7；95% CI：0.3、11；P = .56）。结论 已确诊 COVID-19 突破性感染且完全接种疫苗的患者在胸部 CT 上 COVID-19 典型表现的真阳性发现率较低。© RSNA，2022 补充材料可用于本文。