# The Safety of Ultrasound Contrast Agents in Children

## TL;DR

This study analyzed the safety of contrast-enhanced ultrasound in children and found it to be generally safe with minimal adverse reactions.

## Contribution

The study provides new empirical data on the safety profile of contrast-enhanced ultrasound in a large pediatric population.

## Key findings

- The overall adverse reaction incidence rate was 0.436% with no severe reactions observed.
- Most adverse reactions were mild and classified as immediate onset Type B reactions.
- Only one moderate adverse reaction was recorded among 1604 pediatric patients.

## Abstract

Background/Objectives: Retrospective analysis of the safety of contrast-enhanced ultrasound in children. Methods: A retrospective analysis was conducted on children who underwent contrast-enhanced ultrasound (CEUS) examinations at the Children’s Hospital of Chongqing Medical University from 2019 to 2025. Adverse reactions were classified into three grades (mild, moderate, and severe) based on severity. Following the pharmacological classification, the types of adverse reactions are divided into “Type A reactions” and “Type B reactions” and further classified into immediate and delayed reactions according to the timing of occurrence. Results: This study included 1604 pediatric patients who underwent a total of 1924 intravenous CEUS examinations. Seven patients experienced adverse reactions, yielding an overall adverse reaction incidence rate of 0.436% (95% Confidence Interval: 0.18–0.90%). Among these, six reactions were mild (6/7, 85.71%), and one was moderate (1/7, 14.29%). Among the seven patients, 16 clinical manifestations were recorded, comprising 12 type B reactions (12/16, 75%) and 4 type A reactions (4/16, 25%). Furthermore, all adverse reactions were classified as immediate onset. Conclusions: Under the conditions of this study, CEUS demonstrated good safety in the pediatric population, with no serious adverse events observed.