Early screening of lung function by electrical impedance tomography in people with normal spirometry reveals unrecognized pathological features.

Summary

Electrical impedance tomography revealed regional time-constant abnormalities indicative of lung pathology in individuals with normal spirometry. With CT as the reference, EIT-based screening achieved sensitivities of 81.3% (concept phase) and 77.9% (validation phase), highlighting its promise for early detection of subclinical lung dysfunction.

Key Findings

• In people with normal spirometry, EIT detected abnormal regional time constants consistent with unrecognized pathology.
• CT-referenced sensitivity was 81.3% in the concept phase and 77.9% in the validation phase; specificity was 50%.
• The study underscores that spirometry may miss early regional dysfunction measurable by EIT.

Clinical Implications

EIT could complement spirometry to flag high-risk individuals for confirmatory imaging and early intervention, potentially preventing progression to overt disease.

Limitations

• Specificity was modest (50%), and CT confirmation was performed in subsets flagged by EIT or smoking history, introducing selection bias.
• Cross-sectional design without longitudinal clinical outcomes.

Future Directions

Longitudinal studies linking EIT abnormalities to clinical outcomes, optimization of thresholds, and integration into risk-based screening pathways.