Contrast-enhanced ultrasound using sulfur hexafluoride is safe in the pediatric setting

Background: Contrast-enhanced ultrasound (CEUS) by using sulfur hexafluoride microbubbles is not licensed for use in children, but its off-label use is widespread. Purpose: To outline our experience with the off-label use of CEUS in children, specifically with regards to safety. Material and Methods: We retrieved all records of 10681 patients aged under 18 years who underwent abdominal ultrasound (US) January 2004 to December 2014. We then identified those who underwent an abdominal CEUS using sulfur hexafluoride microbubbles. Electronic patient charts were used to verify the indication for contrast agent, dose, possible adverse effects as well as information on patient height, weight, and age. Results: We identified 173 patients (mean age, 11 years; range, 0.1-18 years) who underwent a total of 287 CEUS exams. Of all exams, 46% were performed on the native liver, 31% on a transplanted liver, and 23% on other organs. The indications were "circulatory status?'' (40%), "characterization of lesion?'' (40%), and miscellaneous (20%). Mean contrast dose was 2.3 mL (range, 0.1-8.1 mL). No immediate adverse effects were recorded. One patient experienced itching the day after, but this was considered to be a reaction to concomitantly administered fentanyl. Conclusion: The use of intravenous ultrasound contrast seems safe in patients aged under 18 years and our results do not support the current practice to restrict the use of CEUS in children.