Influence of ECG-triggered data acquisition on reliability for carotid plaque volume measurements with a magnetic sensor three-dimensional ultrasound system

Three-dimensional (3D) ultrasound reconstructions of the carotid arteries are based on multiple sections of two-dimensional data. Some 3D systems use an electrocardiography (ECG)-triggered data acquisition for 3D reconstructions of pulsatile vessels such as carotid arteries. No systematic comparison of 3D data, acquired with and without ECG triggering, has been reported. We used a new magnetic sensor system allowing freehand scanning for data acquisition. Our aim was to test the effect of ECG triggering on the reliability of plaque volume measurements in the carotid arteries. Data acquisition in the carotid arteries in 25 patients (one plaque from each patient) was performed using two different procedures for data acquisition: 1) a magnetic sensor system for a data acquisition without ECG-triggering, and 2) a magnetic sensor system with ECG-triggered data acquisition. All plaque volumes were measured using manual tracing of the outlines of the plaques. The following reliability data (mean values) were obtained: magnetic sensor system without ECG triggering: intrareader variability 13.3%, interreader variability 16.7%, follow-up variability 16.3%; magnetic sensor system with ECG triggering: intrareader variability 4.6%, interreader variability 4.5%, follow-up variability 5.2%. Carotid plaque volume measurements obtained using a magnetic sensor system with freehand scanning and ECG triggering is highly reliable. ECG triggering is necessary, because a magnetic sensor system without ECG triggering resulted in reduced reliability for plaque volume measurements.