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. 2023 Sep;164(3):700-716.
doi: 10.1016/j.chest.2023.03.024. Epub 2023 Mar 24.

Longitudinal Lung Function Assessment of Patients Hospitalized With COVID-19 Using 1H and 129Xe Lung MRI

Laura C Saunders  1 , Guilhem J Collier  1 , Ho-Fung Chan  1 , Paul J C Hughes  1 , Laurie J Smith  1 , J G R Watson  2 , James E Meiring  2 , Zoë Gabriel  2 , Thomas Newman  3 , Megan Plowright  2 , Phillip Wade  2 , James A Eaden  1 , Siby Thomas  1 , Scarlett Strickland  2 , Lotta Gustafsson  2 , Jody Bray BSc  1 , Helen Marshall  1 , David A Capener  1 , Leanne Armstrong  1 , Jennifer Rodgers  1 , Martin Brook  1 , Alberto M Biancardi  1 , Madhwesha R Rao  1 , Graham Norquay  1 , Oliver Rodgers  1 , Ryan Munro  1 , James E Ball  1 , Neil J Stewart  1 , Allan Lawrie  1 , R Gisli Jenkins  4 , James T Grist  5 , Fergus Gleeson  6 , Rolf F Schulte  7 , Kevin M Johnson  8 , Frederick J Wilson  9 , Anthony Cahn  9 , Andrew J Swift  1 , Smitha Rajaram  2 , Gary H Mills  1 , Lisa Watson  2 , Paul J Collini  1 , Rod Lawson  2 , A A Roger Thompson  3 , Jim M Wild  10
Affiliations

Longitudinal Lung Function Assessment of Patients Hospitalized With COVID-19 Using 1H and 129Xe Lung MRI

Laura C Saunders et al. Chest. 2023 Sep.

Abstract

Background: Microvascular abnormalities and impaired gas transfer have been observed in patients with COVID-19. The progression of pulmonary changes in these patients remains unclear.

Research question: Do patients hospitalized with COVID-19 without evidence of architectural distortion on structural imaging exhibit longitudinal improvements in lung function measured by using 1H and 129Xe MRI between 6 and 52 weeks following hospitalization?

Study design and methods: Patients who were hospitalized with COVID-19 pneumonia underwent a pulmonary 1H and 129Xe MRI protocol at 6, 12, 25, and 51 weeks following hospital admission in a prospective cohort study between November 2020 and February 2022. The imaging protocol was as follows: 1H ultra-short echo time, contrast-enhanced lung perfusion, 129Xe ventilation, 129Xe diffusion-weighted, and 129Xe spectroscopic imaging of gas exchange.

Results: Nine patients were recruited (age 57 ± 14 [median ± interquartile range] years; six of nine patients were male). Patients underwent MRI at 6 (n = 9), 12 (n = 9), 25 (n = 6), and 51 (n = 8) weeks following hospital admission. Patients with signs of interstitial lung damage were excluded. At 6 weeks, patients exhibited impaired 129Xe gas transfer (RBC to membrane fraction), but lung microstructure was not increased (apparent diffusion coefficient and mean acinar airway dimensions). Minor ventilation abnormalities present in four patients were largely resolved in the 6- to 25-week period. At 12 weeks, all patients with lung perfusion data (n = 6) showed an increase in both pulmonary blood volume and flow compared with 6 weeks, although this was not statistically significant. At 12 weeks, significant improvements in 129Xe gas transfer were observed compared with 6-week examinations; however, 129Xe gas transfer remained abnormally low at weeks 12, 25, and 51.

Interpretation: 129Xe gas transfer was impaired up to 1 year following hospitalization in patients who were hospitalized with COVID-19 pneumonia, without evidence of architectural distortion on structural imaging, whereas lung ventilation was normal at 52 weeks.

Keywords: (129)Xe; COVID-19; MRI; gas transfer; hyperpolarized gas; imaging; xenon MRI.

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Figures

Figure 1
Figure 1
A-B, Illustrative diagram showing how the lung MRI techniques used in this article measure lung perfusion, ventilation, lung microstructure (diffusive length scale), and xenon gas transfer (the transfer of xenon between the airspace, membrane, and RBCs). A, Techniques in a healthy alveolus. B, Possible interpretation of the findings of this article in patients who have had COVID-19, with reduced RBC:M due to damage to pulmonary microcirculation but preserved acinar airway dimensions. RBC:M = RBC to membrane fraction.
Figure 2
Figure 2
Flow chart of patient recruitment. UKILD = UK Interstitial Lung Disease Long-COVID-19 study.
Figure 3
Figure 3
Example of UTE images, RBC:M maps, 129Xe ventilation images, and maps of pulmonary blood flow at visit 1 and visit 2, for each patient. The white arrow indicates a segmental perfusion defect visible at visit 1, which improves at visit 2. M = membrane; PBF = pulmonary blood flow; RBC:M = RBC to membrane fraction; UTE = ultra-short echo time.
Figure 4
Figure 4
Spaghetti plots of ventilation, dissolved phase xenon, and dynamic contrast-enhanced lung perfusion metrics at visits 1 to 4. CV = coefficient of variation of lung ventilation; M = membrane; M:gas = membrane to gas fraction; RBC:gas = RBC to gas fraction; RBC:M = RBC to membrane fraction; VDP = ventilation defect percentage.
Figure 5
Figure 5
Lung RBC:M maps in three patients with four MRI visits at 6, 12, 25, and 51 weeks following hospital admission. Mean RBC:M at each visit is shown. M = membrane; RBC:M = RBC to membrane fraction.
Figure 6
Figure 6
Boxplots of xenon gas transfer ratios from patients at visits 1 to 4 as well as metrics from an age- and sex-matched healthy cohort. Open circles denote data > 1.5 interquartile range; star denotes data > 3 interquartile range. M = membrane.; M:gas = membrane to gas fraction; RBC:gas = RBC to gas fraction; RBC:M = RBC to membrane fraction.
Figure 7
Figure 7
Spaghetti plots of FEV1z score, FVC z score, FEV1/FVC z score, KCOz score, and TLCOz score. KCO = carbon monoxide transfer coefficient; TLCO = transfer factor for carbon monoxide.
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References

    1. Lang M., Som A., Carey D., et al. Pulmonary vascular manifestations of COVID-19 pneumonia. Radiol Cardiothorac Imaging. 2020;2(3) - PMC - PubMed
    1. Loo J., Spittle D.A., Newnham M. COVID-19, immunothrombosis and venous thromboembolism: biological mechanisms. Thorax. 2021;76(4):412–420. - PubMed
    1. Attaway A.H., Scheraga R.G., Bhimraj A., Biehl M., Hatipoglu U. Severe Covid-19 pneumonia: pathogenesis and clinical management. BMJ. 2021;372:n436. - PubMed
    1. Robey R.C., Kemp K., Hayton P., et al. Pulmonary sequelae at 4 months after COVID-19 infection: a single-centre experience of a COVID follow-up service. Adv Ther. 2021;38(8):4505–4519. - PMC - PubMed
    1. Stewart N.J., Smith L.J., Chan H.F., et al. Lung MRI with hyperpolarised gases: current & future clinical perspectives. Br J Radiol. 2022;95(1132) - PMC - PubMed

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