軽度/中等度と重度/重症のコロナウイルス疾患2019年患者の回復期CT特徴の比較

[Comparison of Recovery Phase CT Features between Mild/moderate and Severe/critical Coronavirus Disease 2019 Patients].

• Wenbin Zou
• Changyu Liu
• Yixin Cai
• Zhilin Zeng
• Ni Zhang
• Xiangning Fu

抄録

回復期にあるコロナウイルス疾患2019(COVID-19)の軽・中等症および重症・重症症例のコンピュータ断層撮影(CT)の特徴を調査することを目的とした。 中国武漢市で，2020年2月1日から2月29日までに胸部CTと逆転写ポリメラーゼ連鎖反応（RT-PCR）の両方を受けた63名の退院患者を対象とし，RT-PCRをゴールドスタンダードとして，COVID-19の診断における胸部CTの性能を評価した．患者を病状に応じて軽・中等症群と重症・重症群に分け、性別、年齢、症状、入院期間、併存疾患、酸素療法などの臨床的特徴を収集し、回復期のCT画像を発症からの時間、CTの特徴、病変の位置、ローブスコア、CT総スコアでレビューした。 CT画像は軽・中等度群37例、重症・重症群26例であった。重症・重症患者は軽症・中等症患者に比べて年齢が高く［(43±16)年(52±16)年; =2.10, =0.040］，入院期間が長く［(15±6)d(19±7)d; =2.70, =0.009］，重症・重症患者の方が高齢であり，重症・重症患者の方が入院期間が長い［(15±6)d(19±7)d; =2.70, =0.009］．009]、呼吸困難率の上昇（5.41% 53.85%;=18.90、<0.001）、経鼻酸素療法率の低下（81.08% 19.23%;=23.66、<0.001）、2値陽圧換気率の上昇（0 57.69%;=25.62、<0.001）が認められた。発症からの期間は重症/重症患者では（23±6）日で、軽症/中等症患者では（18±7）日に比べて有意に長かった（=3.40、<0.001）。重症/重症患者では、軽症/中等症患者に比べてクレイジーパヴィングパターンの割合が有意に高く（46.15% 10.81% =4.24, =0.039）、グランドガラスの不透明度の割合が低かった（15.38% 67.57% =16.74, <0.001）。肺末梢部の病変の割合は重症/重症患者よりも軽度/重症患者の方が有意に高く（78.38% 34.61%; =13.43、<0.001）、びまん性病変の割合は重症/重症患者の方が軽度/重症患者よりも有意に高く（65.38% 10.81%; =20.47、<0.001）、重症/重症患者の方が重症/重症患者の方が重症/重症患者よりも有意に高かった。また、重症/重症群のCT総得点も軽症/中等症群に比べて重症/重症群で有意に高かった[11(8,17)点 7(4,9)点;=3.81、<0.001]。 回復期のCT特徴は軽度/中等度と重度/重症のCOVID-19患者で異なり，肺浸潤は後者の方が顕著に重症である．

To investigate the computed tomographc(CT)features of mild/moderate and severe/critical cases of coronavirus disease 2019(COVID-19)in the recovery phase. Totally 63 discharged patients in Wuhan,China,who underwent both chest CT and reverse transcription-polymerase chain reaction(RT-PCR)from February 1 to February 29,2020,were included.With RT-PCR as a gold standard,the performance of chest CT in diagnosing COVID-19 was assessed.Patients were divided into mild/moderate and severe/critical groups according to the disease conditions,and clinical features such as sex,age,symptoms,hospital stay,comorbidities,and oxygen therapy were collected.CT images in the recovery phase were reviewed in terms of time from onset,CT features,location of lesions,lobe score,and total CT score. There were 37 patients in the mild/moderate group and 26 in the severe/critical group. Compared with the mild/moderate patients,the severe/critical patients had older age [(43±16) years (52±16) years; =2.10, =0.040], longer hospital stay [(15±6)d (19±7)d; =2.70, =0.009], higher dyspnea ratio (5.41% 53.85%; =18.90, <0.001), lower nasal oxygen therapy ratio (81.08% 19.23%;=23.66, <0.001), and higher bi-level positive airway pressure ventilation ratio (0 57.69%; =25.62, <0.001). Time from onset was (23±6) days in severe/critical group, significantly longer than that in mild/moderate group [(18±7) days] (=3.40, <0.001). Severe/critical patients had significantly higher crazy-paving pattern ratio (46.15% 10.81%;=4.24, =0.039) and lower ground-glass opacities ratio (15.38% 67.57%; =16.74, <0.001) than the mild/moderate patients. The proportion of lesions in peripheral lung was significantly higher in mild/moderate group than in severe/critical group (78.38% 34.61%; =13.43, <0.001), and the proportion of diffusely distributed lesions was significantly higher in severe/critical group than in mild/moderate group (65.38% 10.81%; =20.47, <0.001). Total CT score in severe/critical group was also significantly higher in severe/critical group than in mild/moderate group [11 (8,17) points 7 (4,9) points; =3.81, <0.001]. The CT features in the recovery stage differ between mild/moderate and severe/critical COVID-19 patients.The lung infiltration is remarkably more severe in the latter.