Accuracy of 3D Electrical Impedance Tomography for Assessing Lung Ventilation

N/ANot Yet RecruitingNCT07756086

Shanghai Zhongshan Hospital50 enrolled

Overview

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 Type

OBSERVATIONAL

Enrollment

Conditions

Pulmonary Ventilation

Interventions

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.

Dynamic Chest Computed TomographyDIAGNOSTIC_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.

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

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

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.

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.

Secondary Outcomes

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

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.

Time frame: 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

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.