治療後にRT-PCR検査が2回連続陰性となったCOVID-19患者のCTの特徴

CT features of COVID-19 patients with two consecutive negative RT-PCR tests after treatment.

• Zhao Fu
• Ningning Tang
• Yanqing Chen
• Longbai Ma
• Youyong Wei
• Yumin Lu
• Kun Ye
• Hang Liu
• Fen Tang
• Guangyi Huang
• Yingxia Yang
• Fan Xu

抄録

本研究の目的は、治療後に咽頭スワブ検体が2回連続して核酸検査陰性であったCOVID-19患者のCT特徴を明らかにすることである。治療後に2回連続してRT-PCR検査が陰性であったCOVID-19患者46例をレトロスペクティブに検討した。症例を疾患の重症度に応じて中等症群と重症/重症群に分けた。臨床および CT スキャンデータを収集した。肺病変のCT徴候と肺病変のスコアを明らかにした。中等症39例、重症・重症7例を対象とした。CT画像には肺病変が残存していた。中等度症例では末梢部に病変が認められたが、重症・重症例では全肺葉に病変が認められ、中心部と末梢部の両方に病変が認められた。また、混合地ガラス混濁（GGO）と肺の圧密が認められた。重症患者では網状肺間質肥厚を認めた症例が多かった。重症/重症群では、気管支図、胸水、血管拡大、気管支壁肥厚、気管支拡張、胸膜肥厚、胸膜癒着が高頻度に認められた。重症・重症群ではCTスコアが高かった。肺病変は2回連続して核酸検査が陰性であっても持続していた。核酸検査転換後も定期的にCT検査のフォローアップを行うことを強く推奨した。完全寛解の評価は胸部CTを基本とすべきである。

The objective of this study is to expound the CT features of COVID-19 patients whose throat swab samples were negative for two consecutive nucleic acid tests after treatment. We retrospectively reviewed 46 COVID-19 patients with two consecutive negative RT-PCR tests after treatment. The cases were divided into moderate group and severe/critical group according to disease severity. Clinical and CT scanning data were collected. CT signs of pulmonary lesions and the score of lung involvement were expounded. Thirty-nine moderate cases and seven severe/critical cases were included. Residual pulmonary lesions were visible in CT images. Moderate patients showed peripheral lesions while severe/critical cases exhibited both central and peripheral lesions with all lobes involvement. Mixed ground glass opacity (GGO) and pulmonary consolidation were noted. A larger proportion of severe patients showed reticular pulmonary interstitium thickening. Air bronchogram, pleural effusion, vascular enlargement, bronchial wall thickening, bronchiectasis, pleural thickening and pleural adhesion were more frequently observed in severe/critical group. The severe/critical group showed higher CT score. Pulmonary lesions persisted even after twice consecutive negative nucleic acid tests. We strongly recommended regular follow-up of CT scans after nucleic acid tests conversion. Evaluation of complete remission should base on chest CT.