US findings of melamine-related renal disorders in Hong Kong children.

Background: The melamine-tainted milk incident has caused renal disorders in more than 290,000 children from mainland China since the start of the outbreak in 2008. Since then, more than 27,000 children in Hong Kong have undergone renal US screening.

Objective: To present and discuss the US features of melamine-related renal abnormalities in Hong Kong children.

Materials And Methods: Between September 2008 and February 2009, 3,835 children attended the Department of Radiology of Princess Margaret Hospital for renal US examination. CT or plain abdominal radiography was performed in those with inconclusive findings. The US findings of detected melamine-related renal disorders were analysed.

Results: Echogenic foci in the kidneys were found in 22 children (0.6%). These were located in the renal pelvicalyceal system (in 12 children) and in the renal medulla (in 10 children). The echogenic foci measured 0.1-0.7 cm, with 6 children showing posterior acoustic shadowing, 14 showing comet-tail artefacts, and 2 showing echogenic dots.

Conclusion: The incidence of renal disorders amongst Hong Kong children exposed to melamine was lower than in their mainland China counterparts. The renal stones detected were also relatively small, with most demonstrating comet-tail artefacts instead of posterior acoustic shadowing.