Three-dimensional reconstruction of the vessel lumen as an adjunct to the cerebrovascular duplex evaluation

Introduction. - Color-flow duplex ultrasound is effective in the detection and quantification of carotid artery disease; however, diameter reduction estimates are most commonly derived by Doppler velocity measurements. In addition, direct visualization of the vessel lumen is only possible through the use of more expensive potentially invasive imaging procedures, such as computed tomography angiography, magnetic resonance angiography, and conventional angiography. Described here is a method to determine vessel diameter of the internal carotid artery (ICA) by the use of three-dimensional (3D) reconstruction of b-mode data to generate luminal diameter estimates. Materials and Methods. - A prospective review of 40 consecutive cerebrovascular duplex studies was performed. Testing protocols required transverse sweeps of the common carotid artery (CCA) and ICA in b-mode. Motion files were analyzed using software, which segmented the vessel lumen as the area of interest. The software created a 3D rendering of the lumen of the CCA and ICA. Vessel diameter reduction estimated by Doppler-derived velocities was then compared with the 3D rendering of the vessel lumen diameters. Results. - There was a 99% (n = 79, ρ = < 0.001) correlation between velocity estimates and 3D visualization for estimating diameter reduction. Correlation for cases with less than 50% diameter reduction by duplex was 100% (n = 66, ρ = < 0.004), whereas correlation for cases with 50% or greater diameter reduction by duplex was 92% (n = 13, ρ = < 0.03). Conclusion. - 3D reconstruction of the vessel lumen shows a statistically significant correlation with velocity-derived diameter reduction measurements. Although more investigation with a larger group of patients is necessary, 3D reconstruction may be a valuable adjunct and may enhance the diagnostic capabilities of color-flow duplex ultrasound.