Introduction and objective: Ultrasonography is the first-line imaging method for evaluating kidneys in children. Computed tomography (CT) or magnetic resonance imaging (MRI) are often needed to increase diagnostic certainty. However, these modalities involve patient’s exposure to ionising radiation, adverse effects of contrast agents and sometimes general anaesthesia. Contrast-enhanced ultrasonography (CEUS) has become a recognised diagnostic tool in many countries. It is used for the imaging of various organs in adults. In Europe, intravenous administration of ultrasound contrast agents for abdominal organ assessment is generally not approved for patients under 18 years of age. However, an increasing amount of published data indicates the usefulness and safety of CEUS in children. The aim of the study was to assess the usefulness of CEUS in differentiating focal renal lesions and assessing perfusion of transplanted kidneys. Materials and methods: The study included 18 patients, with a total of 28 CEUS kidney examinations performed. CEUS results were categorised into three groups (benign focal lesions, malignant focal lesions, perfusion disorders of the transplanted kidney) and were compared with reference CT or MRI findings. Results: CEUS identified benign focal lesions in 9 out of 14 (64%) patients, potentially malignant lesions in 5 out of 14 (36%) patients, and ischaemic foci in 2 out of 4 (50%) kidney transplant recipients. Comparison of definitive CEUS findings with reference results showed full agreement. Conclusions: CEUS is a useful tool for differentiating focal lesions and monitoring ischaemic renal foci in paediatric patients. CEUS may reduce the number of reference CT and MRI scans in the future. However, the use of CEUS in paediatric diagnosis requires further research.

children, contrast-enhanced ultrasonography (CEUS), ultrasound contrast agent (UCA), focal kidney lesions, transplanted kidney