Contrast-enhanced ultrasound in children

Abstract

Background: Contrast-enhanced ultrasound (CEUS) is a diagnostic tool that is used for many applications in adults. Many of these applications are considered “off-label” use but still play an important role in diagnostic imaging. In Europe, and most other countries worldwide, all pediatric CEUS use is 'off-label', regardless of the specific application. However, there is mounting experience and documentation to support its safe and effective use in children and adults alike. Nonetheless, there may be some apprehension among physicians when considering CEUS for children, partly due to the lack of official licensing. In Karolinska University Hospital, Huddinge, CEUS has successfully been utilized in children for over two decades.

Aims: To analyze and present our experience with pediatric CEUS at Karolinska University Hospital, Huddinge and to survey the use of pediatric CEUS in Nordic hospitals.

Material and methods: Studies 1-3. We retrieved the records of 10681 patients under the age of 18 who underwent abdominal ultrasonography (US) January 2004 to December 2014. We then identified those who underwent CEUS using sulfur hexafluoride microbubbles. Electronic patient charts were used to gather clinical information on the cases such as indication for the exam, lab results, patho-histologic results etc. Also, anthropometric data was collected. The hospital Picture archiving and communication systems (PACS) was used to retrieve relevant radiology reports and information on administered contrast dose. Study 4. Radiologists in Nordic hospitals in 2022 were surveyed trough a web questionnaire.

Results: Study 1 suggests that CEUS is safe in the pediatric population with no severe adverse effects recorded. Study 2 suggests that CEUS can be used to identify circulatory complications after liver transplantation. Moreover, CEUS may be valuable as a “problem solving - tool”, particularly when the unenhanced ultrasonography is inconclusive. Study 3 suggests that CEUS has a place in the characterization of focal liver lesions and in select cases it can rule out a malignant lesion without the need for further workup. Study 4 suggests that CEUS is widely used in many Nordic countries and the main reasons for its use was reported to be that CEUS could result in fewer alternative exams such as Computed tomography (CT) and Magnetic resonance imaging (MRI) and hence decrease the amount of ionizing radiation and sedation. The main obstacle for its use was reported to be lack of experience and of official licensing.

Conclusions: Our findings support the continued use of CEUS in children and further reinforces its place as a safe alternative and/or compliment to CT and MRI. It also highlights the perceived advantages and obstacles for its continued use in the Nordic countries. Much could be gained from allowing official licensing for pediatric CEUS.