3-D Contrast-Enhanced Fusion Ultrasound for Accurate Volume Assessment of Vessel Lumen and Plaque in Carotid Artery Disease as Compared With Computed Tomography Angiography

Abstract

ObjectiveThree-dimensional contrast-enhanced fusion ultrasound (3D-CEFUS) of atherosclerotic carotid arteries provides spatial visualisation of the vessel lumen, creating a lumenography. As in 3D computed tomography angiography (3D-CTA), 3D-CEFUS outlines the contrast-filled lumen. Plaque and vessel contours are distinguished in 3D-CEFUS, allowing plaque volume quantification as a valid estimate of carotid plaque burden. 3D-CEFUS is unproven in inter-modality studies, vindicating the assessment of 3D-CEFUS applicability and comparing 3D-CEFUS and 3D-CTA lumenography as a proof-of-concept study. MethodsUsing an ultrasound system with magnetic tracking, a linear array transducer, and SonoVue contrast agent generated 3D-CEFUS acquisitions by spatial stitching of serial 2D images. From 3D-CEFUS and 3D-CTA imaging, the atherosclerotic carotid arteries were reconstructed with lumenography in an offline software programme for lumen and plaque volume quantification. Bland-Altman analysis was used for inter-image-modality agreement. ResultsThe study included 39 carotid arteries. Mean lumen and plaque volume in 3D-CEFUS were 0.63 cm3 (SD 0.26) and 0.62 cm3 (SD 0.26), respectively. Lumen volume differences between 3D-CEFUS and 3D-CTA were non-significant, with mean difference of 0.01 cm3 (SD 0.02, p = .26) and limits of agreement range (LoA-range) of ±0.11 cm3. Mean plaque volume difference was -0.12 cm3 (SD 0.19, p = .006) with LoA-range of ±0.39 cm3. ConclusionStrong agreement in lumenography between 3D-CEFUS and 3D-CTA was found. The inter-image-modality difference in plaque volumes was substantial due to challenging vessel wall definition in 3D-CTA. 3D-CEFUS is viable in quantifying carotid plaque volume burden and can potentially monitor plaque development over time.