Relation of impulse oscillometry and spirometry with quantitative thorax computed tomography after COVID-19 pneumonia

Abstract

SUMMARY OBJECTIVE: This study aimed to investigate if there is any correlation between the quantitative computed tomography and the impulse oscillometry or spirometry results of post-COVID-19 patients. METHODS: The study comprised 47 post-COVID-19 patients who had spirometry, impulse oscillometry, and high-resolution computed tomography examinations at the same time. The study group consisted of 33 patients with quantitative computed tomography involvement, while the control group included 14 patients who did not have CT findings. The quantitative computed tomography technology was used to calculate percentages of density range volumes. The relationship between percentages of density range volumes for different quantitative computed tomography density ranges and impulse oscillometry-spirometry findings was statistically analyzed. RESULTS: In quantitative computed tomography, the percentage of relatively high-density lung parenchyma, including fibrotic areas, was 1.76±0.43 and 5.65±3.73 in the control and study groups, respectively. The percentages of primarily ground-glass parenchyma areas were found to be 7.60±2.86 and 29.25±16.50 in the control and study groups, respectively. In the correlation analysis, the forced vital capacity% predicted in the study group was correlated with DRV% [(-750)-(-500)] (volume of the lung parenchyma that has density between (-750)-(-500) Hounsfield units), but no correlation with DRV% [(-500)-0] was detected. Also, reactance area and resonant frequency were correlated with DRV% [(-750)-(-500)] , while X 5 was correlated with both DRV% [(-500)-0] and DRV% [(-750)-(-500)] density. Modified Medical Research Council score was correlated with predicted percentages of forced vital capacity and X 5 . CONCLUSION: After COVID-19, forced vital capacity, reactance area, resonant frequency, and X 5 correlated with the percentages of density range volumes of ground-glass opacity areas in the quantitative computed tomography. X 5 was the only parameter correlated with density ranges consistent with both ground-glass opacity and fibrosis. Furthermore, the percentages of forced vital capacity and X 5 were shown to be associated with the perception of dyspnea.

Post-Infection Oscillometry and Pulmonary Metrics in SARS-CoV-2 Patients: A 40-Day Follow-Up Study

“…Nevertheless, these traditional methods, although informative, might not capture all the functional and structural alterations post-SARS-CoV-2 infection, such as small airway disfunction, which was more evident in some studies when using oscillometry methods [ 11 , 12 ]. Forced oscillometry, a noninvasive technique for measuring respiratory impedance, provides additional parameters of respiratory mechanics not typically obtained from conventional spirometry or body plethysmography.…”

Radiological and Functional Pulmonary Evolution in Post-COVID-19 Patients: An Observational Study

“…In addition to the characteristic clinical scenario that may occur and the various radiographic images that should be evaluated, checking pulmonary function (spirometry) is an essential part of the follow-up appointments of these affected patients [ 19 , 20 , 21 ]. The predictive values are determined in accordance with the Global Lung Function Initiative [ 20 , 22 ].…”