Table 3 Suggested procedure for renal sonography in children at risk of Wilms's tumour.

Equipment	High‐resolution probes and paediatric settings. Linear (7–10 MHz) in infants, curvilinear (6–8 MHz) probe in toddlers
Preparation	Fasting and bladder preparation are not required
Target organ	Kidney only
Technique	Appropriate focal point and time gain settings. The whole renal parenchyma should be imaged longitudinally and transaxially with the child both supine and prone
Normal variants	Dromedary hump, column of Bertin, duplex or bifid collecting systems
Suspicious lesions	Solitary or multiple cystic or solid parenchymal lesions with or without sonographic signs of expansile growth. A solid lesion with internal vascular flow is more likely to represent malignancy than a simple cystic anechoic lesion