Ultrasound Assessment of Aortic and Carotid Artery Intima-media Thickness in Children and Adolescents

Summary

The present article describes the methodological considerations for the noninvasive assessment of abdominal aortic and carotid intima-media thickness using B-mode ultrasonography. This technique is commonly used in the developmental origins of health and disease research as a surrogate for early arterial changes.

Abstract

Carotid intima-media thickness (IMT), measured using high-resolution B-mode ultrasonography, is a widely utilized surrogate marker of subclinical atherosclerosis, the pathophysiological process underlying most clinical cardiovascular disease events. Atherosclerosis is a gradual disease that originates early in life, thus, there has been increased interest in measuring carotid IMT in childhood and adolescence to assess structural change in the arterial vasculature in response to adverse exposures. However, the timing of atherosclerosis varies across the vascular tree. Primordial atherosclerotic lesions are present in the abdominal aorta as early as infancy, compared to mid-adolescence for the common carotid. Measurement of IMT at either site is susceptible to several technical challenges that need to be considered, especially in younger children. In this paper, we provide a detailed stepwise method for high-quality assessment of IMT of the abdominal aorta and common carotid artery in the young. We also provide insight into the appropriateness of either site when exploring the associations between early-life exposures and later-life cardiovascular disease.

Introduction

The Developmental Origins of Health and Disease (DoHAD) hypothesis proposes a link between environmental exposures during critical periods of development - from conception to 2 years of age - and later-life susceptibility to cardiometabolic diseases¹. Several observational studies have shown that exposures in the perinatal period, such as low birth weight and pre-term birth, are associated with longer-term cardiovascular disease (CVD) risk². Atherosclerosis, the gradual thickening of the two innermost layers of the arterial wall, is a precursor to most clinical CVD events³. This thickening can be ....

Protocol

All research was performed in compliance with the Sydney Local Health District Human Research Ethics Committee (Protocol Nos. X16-0065 and X15-0041). All ultrasound images are free of identifying information. Images used to illustrate transducer placement were performed on individuals with their consent or with consent from their parent or guardian for those unable to provide consent.

1. Common carotid intima-media thickness

1. Ask the participant to lie down on the bed without a pillow. This will help keep the neck as straight as possible.
2. Ask the examiner to be positioned at the head of the participant ....

Results

In this section, we represent results from prior studies to highlight key aspects of cIMT and aIMT measurement. Figure 1 and Figure 2 focus on cIMT, demonstrating both transverse and longitudinal views in young, healthy subjects and a detailed visualization of the IMT complex. Figure 3 and Figure 6 further emphasize best practices based on the positioning of the bulb, image settings, as well as semi-aut.......

Discussion

The present manuscript provides guidance on the acquisition and analysis of ultrasound images to measure aIMT and cIMT, specifically in younger populations (ages 0-18). Both techniques have demonstrated utility in exploring the influence of early life exposures on atherosclerosis but are susceptible to technical challenges, which we discuss below.

Critical steps in protocol implementation
Ultrasound system and settings: Acquisition of high-quality B-mode.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
12-3 MHz Broadband linear array transducer	Phillips	L12-3
Meijer's Carotid Arc	Meijer	-
Semi-automated edge detection analysis software	Medical Imaging Applications	Carotid Analyzer 5
Ultrasound	Phillips	Epiq 7
Ultrasound transmission gel	Parker	01-08