Respiration monitor for computed tomography

A diagnostic imaging system including:

• a diagnostic imaging scanner that acquires imaging data of a subject in an examination region;
• a reconstruction processor that reconstructs the acquired imaging data into an image representation;
• a pair of electrodes adapted to externally contact a thoracic region of the subject;
• an electrical meter that measures a time-varying electrical parameter across the electrode pair by applying a voltage or current pulse train having a frequency substantially higher than the heart rate across the pair of electrodes;
• a monitor that extracts a time-varying respiration characteristic from the measured time-varying electrical parameter, the monitor including a respiratory cycle phase processor that estimates a respiratory cycle phase based on the time varying electrical parameter;
• and
• an imaging controller that receives the respiration characteristic and controls the diagnostic imaging scanner based thereon.

A diagnostic imaging system including:

• a diagnostic imaging scanner that acquires imaging data of a subject in an examination region;
• a reconstruction processor that reconstructs the acquired imaging data into an image representation;
• a pair of electrodes adapted to externally contact a thoracic region of the subject;
• an electrical meter that measures a time-varying electrical parameter across the electrode pair by applying a voltage or current pulse train having a frequency substantially higher than the heart rate across the pair of electrodes;
• a monitor that extracts a time-varying respiration phase characteristic from the measured time-varying electrical parameter;
• an electrocardiograph that measures electrocardiographic data of the subject using at least the pair of electrodes;
• and
• an imaging controller that receives the respiration characteristic and controls the diagnostic imaging scanner based thereon.

A medical diagnostic imaging method including:

• acquiring imaging data of a medical imaging patient;
• reconstructing at least a part of the acquired imaging data into an image representation;
• externally contacting a thoracic region of the patient with the pair of external electrodes;
• measuring a time-varying electrical parameter across the external electrodes pair during the acquiring of imaging data, the measuring including applying one of a voltage and a current to the external electrodes pair, measuring the other of voltage and current responsive to the applying, and computing the time-varying electrical parameter based on the applied and measured quantities;
• computing a time-varying respiration characteristic based on the measured time-varying electrical parameter wherein the computing of a time-varying respiration characteristic from the time-varying electrical parameter includes computing a time varying respiratory cycle phase function based on the time-varying electrical parameter;
• and
• adjusting an imaging parameter responsive to the respiration characteristic.