Comparison of Carotid Artery Peak Systolic Velocity Measurement Guided by 2-Dimensional Versus 3-Dimensional X-Plane...

Characterisation of carotid artery stenosis by Doppler ultrasound relies on peak systolic velocity (PSV) measurements and velocity ratios. The site of PSV sampling is conventionally guided by 2-dimensional (2D) colour Doppler in the longitudinal plane only. The recently introduced Philips eXL14-3 MHz matrix array transducer (Philips Ultrasound, Bothell, WA, USA) allows visualisation of colour Doppler in longitudinal and transverse planes simultaneously (3D). We compared PSV measurements of the mid common carotid artery (mCCA) obtained using conventional 2D guidance versus 3D ultrasound guidance in a series of 100 carotid arteries.

This was a single centre prospective study of 100 mCCA velocity measurements. All ultrasound examinations were performed by a single qualified vascular sonographer. 2D-guided and 3D-guided PSV measurements were made. Sample volume adjustments made by the sonographer were recorded.

The average difference in PSV across the 100 sample sets was 0.3 ± 5.9 SD cms^-1. Comparing 3D versus 2D guided measurements, 45 samples showed an increase in PSV measurement, with an average of 5.0 cms^-1; 51 samples showed a decrease in PSV, with an average of -3.8 cms^-1 and 4 samples did not show any change. The fitted T- and normal distribution coefficients for the 2D and 3D samples for both the PSV and TAPV were equivalent. The F-tests of the horizontal and vertical adjustments of sample volume in 3D indicate there is little to no relationship between sample gate adjustment and resultant velocity measurements.

No significant difference was observed in PSV measurements of the mCCA when using 3D versus conventional 2D ultrasound guidance.