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NCT Number: NCT07756086

Accuracy of 3D Electrical Impedance Tomography for Assessing Lung Ventilation

This prospective observational study will evaluate how accurately three-dimensional electrical impedance tomography (3D-EIT) measures the distribution of air in the lungs during breathing when compared with four-dimensional computed tomography (4D-CT).

3D-EIT is a noninvasive, radiation-free imaging method that measures changes in electrical impedance across the chest and can provide continuous information about regional lung ventilation. In this study, 4D-CT will be used as the reference method because it can provide detailed images of changes in the lungs throughout the breathing cycle.

Approximately 50 adults, including healthy volunteers and hospitalized patients who are able to undergo both examinations, will be enrolled at a single center. EIT and CT data will be collected at the same time during stable breathing. Researchers will compare the two methods to determine how closely their measurements of ventilation in different lung regions agree. The study will also explore whether EIT can detect changes in regional ventilation under different breathing conditions.

The study will not use the research EIT results to make clinical treatment decisions. The findings may support the future use of EIT as a noninvasive, radiation-free method for monitoring regional lung ventilation.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 18 years or older.
  • Healthy volunteers or patients in the intensive care unit for whom CT imaging is considered necessary based on the treating physician's clinical judgment.
  • Able to cooperate with or undergo simultaneous 4D-CT and 3D-EIT monitoring.
  • Able to provide written informed consent personally or through a legally authorized representative, as applicable.

Exclusion criteria

  • Unable to tolerate or having a contraindication to 4D-CT examination, including pregnancy or severe respiratory distress.
  • Extensive chest skin injury or infection, or any condition preventing placement of the EIT electrode belt.
  • Body size or chest deformity that may substantially limit the quality of EIT or CT data, including chest circumference outside the compatible range of the EIT device.
  • Presence of an implanted electronic device that may interfere with EIT signals, such as a cardiac pacemaker.
  • Unable to complete simultaneous 4D-CT and 3D-EIT monitoring because of significant motion, persistent coughing, poor cooperation, or other technical or clinical reasons.
  • Any other condition that, in the investigator's judgment, makes the individual unsuitable for participation in the study.

Treatment and study plan

Three-Dimensional Electrical Impedance Tomography

Device

Regional lung ventilation data will be collected using a chest electrical impedance tomography system (V200-S). Electrical impedance changes in the chest will be measured continuously and reconstructed to assess three-dimensional regional ventilation distribution. EIT data will be acquired synchronously with dynamic computed tomography data and will be used for research analysis only. The research EIT results will not directly guide clinical treatment decisions.

Other names: 3D-EIT

Dynamic Chest Computed Tomography

Diagnostic Test

Dynamic chest computed tomography data will be acquired using an X-ray computed tomography system (uCT 610 Sim) during one or more breathing cycles. The images will be reconstructed and analyzed to quantify changes in regional lung air volume and ventilation distribution. The 4D-CT measurements will serve as the reference method for comparison with 3D-EIT measurements.

Other names: 4D-CT

Primary outcomes

  1. Deming and Passing-Bablok Regression Slopes and Intercepts Comparing Regional Ventilation Fraction Measured by 3D-EIT and 4D-CT

    Time frame: Periprocedural, during synchronous 3D-EIT and 4D-CT acquisition at the study visit; one respiratory cycle is from the onset of one inspiration to the onset of the next.

    For each participant, paired regional ventilation fraction measurements obtained by 3D-EIT and 4D-CT during the same synchronized respiratory cycle will be analyzed. Regional ventilation fraction will be expressed as the percentage of total ventilation within each predefined lung region. Prespecified regions may include the ventral and dorsal lung regions, dependent and nondependent regions, and the left and right lungs. Agreement between the two methods will be assessed using Deming regression and Passing-Bablok regression. Regression slopes, intercepts, and their 95% confidence intervals will be reported. A slope closer to 1 and an intercept closer to 0 indicate better agreement between the two methods.

Secondary outcomes

  1. Pearson Correlation Coefficient Between Regional Ventilation Fraction Measurements Obtained by 3D-EIT and 4D-CT

    Time frame: Periprocedural, during the synchronous 3D-EIT and 4D-CT acquisition at the study visit

    Paired regional ventilation fraction measurements obtained from spatially and temporally aligned 3D-EIT and 4D-CT ventilation data will be evaluated using the Pearson correlation coefficient. Regional ventilation fraction will be expressed as the percentage of total ventilation within each predefined lung region. Analyses will be performed for predefined regions, including the ventral and dorsal regions, left and right lungs, and dependent and nondependent regions, as applicable. Pearson correlation coefficients and their 95% confidence intervals will be reported.

  2. Mean Bias and 95% Limits of Agreement Between Regional Ventilation Fraction Measurements Obtained by 3D-EIT and 4D-CT

    Time frame: Periprocedural, during the synchronous 3D-EIT and 4D-CT acquisition at the study visit

    Agreement between paired regional ventilation fraction measurements obtained by 3D-EIT and 4D-CT will be evaluated using Bland-Altman analysis. Regional ventilation fraction will be expressed as the percentage of total ventilation within each predefined lung region. The mean difference between the two methods, corresponding 95% confidence interval, and the lower and upper 95% limits of agreement will be reported.

Study contacts

Contact information is provided by the study sponsor or research team.

Sponsors and collaborators

Lead sponsor

Shanghai Zhongshan Hospital

Other

Registry information

Official study title

Accuracy of Three-Dimensional Electrical Impedance Tomography for Assessing Dynamic Regional Lung Ventilation Validated by Four-Dimensional CT: A Prospective Observational Study

Important dates

Study start
2026
Primary completion
2026
Study completion
2027
First posted
Aug 10, 2026
Registry last updated
Aug 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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