Accuracy of 3D Electrical Impedance Tomography for Assessing Lung Ventilation

August 4, 2026 updated by: Shanghai Zhongshan Hospital

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

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.

Study Overview

Study Type

Observational

Enrollment (Estimated)

50

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

The study population will include adults aged 18 years or older recruited at the Department of Critical Care Medicine, Zhongshan Hospital, Fudan University. Participants will consist of healthy volunteers and intensive care unit patients for whom CT imaging is considered necessary based on the treating physician's clinical judgment. Eligible participants must be able to undergo simultaneous 4D-CT and 3D-EIT monitoring.

This is a prospective, observational, single-center study. Participation will not alter the participant's routine clinical management, and the research-derived three-dimensional EIT reconstruction results will not be used directly to make clinical treatment decisions.

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Paired 3D-EIT and 4D-CT Assessment Cohort
This single cohort will include approximately 50 adults, including healthy volunteers and hospitalized patients, who are able to undergo synchronous 3D-EIT and 4D-CT data acquisition. Regional lung ventilation measurements obtained by the two methods during the same breathing cycle will be compared for agreement and accuracy. Participants will not be assigned to different study groups, and the research EIT results will not be used to direct clinical treatment.
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 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
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.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
Periprocedural, during the synchronous 3D-EIT and 4D-CT acquisition at the study visit
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.
Periprocedural, during the synchronous 3D-EIT and 4D-CT acquisition at the study visit

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 1, 2026

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

July 1, 2027

Study Registration Dates

First Submitted

July 30, 2026

First Submitted That Met QC Criteria

August 4, 2026

First Posted (Actual)

August 10, 2026

Study Record Updates

Last Update Posted (Actual)

August 10, 2026

Last Update Submitted That Met QC Criteria

August 4, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • B2026-447

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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