Accuracy of 3D Electrical Impedance Tomography for Assessing Lung Ventilation

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.

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.