Identification of Vascularised Carotid Plaques Using a Standardised and Reproducible Technique to Measure Ultrasound Contrast Uptake

Abstract

We present a reproducible, semi-automatic method to identify vascularisation of carotid plaques, which could be used in prospective studies to determine the clinical value of plaque vascularisation.

Assessment of carotid plaque neovascularization using quantitative analysis of contrast-enhanced ultrasound imaging is useful for risk stratification in patients with coronary artery disease

“…This approach inherently introduces the complication of motion artifacts in the plaque ROI caused by arterial pulsation, breathing or small movements of the probe. Several methods were developed for semi-automated quantitative analysis of CEUS using accurate motion compensated analysis tools [15][16][17]. Recent papers developed a technique to reconstruct intra-plaque neovascularization based on contrast spot motion in plaque [17].…”

“…However, early CEUS studies of the carotid artery were analyzed using a visual-based qualitative approach that may have resulted in inaccurate interpretation and inter-reader variation [7,10,12]. Recent reports developed several techniques for quantitative analysis of CEUS [8,9,11,[13][14][15][16][17][18]. Quantitative analysis of CEUS could improve reproducibility and reduce observer variability [8,9,13,14].…”

Spatio-temporal Quantification of Carotid Plaque Neovascularization on Contrast Enhanced Ultrasound: Correlation with Visual Grading and Histopathology

“…2 EI ¼ enhanced intensity; EIR ¼ enhanced intensity ratio; WT ¼ wash in time. 3 Multiple CEUS image frames are accumulated by specific temporal averaging algorithms such as the temporal mean operation, maximum intensity projection, and contrast quantification program. 4 SA ¼ surface area; AR ¼ area ratio; CDD ¼ center deviation degree; NC ¼ neovessel count.…”

“…Thus, it is difficult to use the visual assessment as a diagnostic tool. 3,4 Quantitative analysis of IPN has recently gained increased interest. There are two types of quantitative analysis, temporal analysis and spatial analysis, which calculate changes in perfusion intensity over time and space, respectively, as illustrated in Fig.…”

“…5,6 The spatial analysis quantifies the UCA spatial distribution. It first accumulates multiple CEUS image frames by specific algorithms such as the temporal mean operation, 7 maximum intensity projection, 8e11 and contrast quantification program (CQP), 3,12 and then computes quantitative variables from the accumulated image, including the IPN surface area (SA), 4,11,13 area ratio (AR), 4,7,8,11 neovessel count (NC), 9 center deviation degree (CDD), 7 radial deviation degree (RDD), 7 and CQP value. 3 The accumulation can be recognized as a step of temporal averaging of multiple images (Fig.…”