Long COVID in Young Patients: Impact on Lung Volume Evaluated Using Multidetector CT

Area of Science:

• Pulmonary Medicine
• Radiology
• Infectious Diseases

Background:

• Long COVID is characterized by persistent mild respiratory symptoms in some individuals.
• Chest CT scans in these patients often appear normal, lacking clear inflammatory findings.
• Quantitative analysis of lung volumes may reveal subtle changes not apparent on standard radiological review.

Purpose of the Study:

• To evaluate for lung volume reduction in Long COVID patients using quantitative analysis of chest CT images.
• To compare lung volumes in post-COVID individuals with mild respiratory symptoms to a non-COVID control group.
• To investigate potential sub-radiological pulmonary changes associated with Long COVID.

Main Methods:

• Retrospective analysis of chest CT scans from young adult patients (18-40 years).
• Quantitative volumetric analysis using AwServer Thoracic VCAR software.
• Exclusion of patients with inflammatory findings, prior lung surgery, cancer, or image artifacts.
• Comparison between a post-COVID group (SARS-CoV-2 positive) and a pre-pandemic non-COVID control group.

Main Results:

• A cohort of 154 patients (77 post-COVID, 77 non-COVID) was analyzed.
• No significant differences in age, sex, obesity, or smoking habits between groups.
• Post-COVID patients showed a statistically significant reduction in total lung volume (5.25 L vs. 5.72 L, p=0.01), right lung volume (2.76 L vs. 3 L, p=0.01), and left lung volume (2.48 L vs. 2.72 L, p=0.01).

Conclusions:

• Quantitative CT analysis demonstrated a mean 10% reduction in lung volume in Long COVID patients compared to controls.
• This quantitative finding suggests sub-radiological lung volume changes in Long COVID, even with negative inflammatory CT findings.
• These results emphasize the utility of quantitative imaging in understanding Long COVID's potential long-term pulmonary effects beyond traditional radiological assessment.