Quantitative inspiratory–expiratory chest CT findings in COVID-19 survivors at the 6-month follow-up

• Published in: Scientific reports Vol. 12; no. 1; pp. 7402 - 12
• Main Authors: Jia, Xi, Han, Xiaoyu, Cao, Yukun, Fan, Yanqing, Yuan, Mei, Li, Yumin, Gu, Jin, Zheng, Yuting, Wang, Li, Qu, Yali, Shi, Heshui
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.05.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 692/308/174; 692/699/255/1578; Carbon monoxide; Chest; Complications; Coronaviruses; COVID-19; COVID-19 - diagnostic imaging; Diffusion; Follow-Up Studies; Humanities and Social Sciences; Humans; Lung - diagnostic imaging; multidisciplinary; Opacity; Respiration; Respiratory function; Retrospective Studies; Risk factors; Science; Science (multidisciplinary); Survivors; Tomography, X-Ray Computed; Trapping
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-11237-1

We evaluated pulmonary sequelae in COVID-19 survivors by quantitative inspiratory–expiratory chest CT (QCT) and explored abnormal pulmonary diffusion risk factors at the 6-month follow-up. This retrospective study enrolled 205 COVID-19 survivors with baseline CT data and QCT scans at 6-month follow-up. Patients without follow-up pulmonary function tests were excluded. All subjects were divided into group 1 (carbon monoxide diffusion capacity [DL CO ] < 80% predicted, n = 88) and group 2 (DL CO  ≥ 80% predicted, n = 117). Clinical characteristics and lung radiological changes were recorded. Semiquantitative total CT score (0–25) was calculated by adding five lobes scores (0–5) according to the range of lesion involvement (0: no involvement; 1: < 5%; 2: 5–25%; 3: 26–50%; 4: 51–75%; 5: > 75%). Data was analyzed by two-sample t-test, Spearman test, etc. 29% survivors showed air trapping by follow-up QCT. Semiquantitative CT score and QCT parameter of air trapping in group 1 were significantly greater than group 2 ( p  < 0.001). Decreased DL CO was negatively correlated with the follow-up CT score for ground-glass opacity (r = − 0.246, p  = 0.003), reticulation (r = − 0.206, p  = 0.002), air trapping (r = − 0.220, p  = 0.002) and relative lung volume changes (r = − 0.265, p  = 0.001). COVID-19 survivors with lung diffusion deficits at 6-month follow-up tended to develop air trapping, possibly due to small-airway impairment.