Pediatric Radiology

, Volume 43, Issue 4, pp 474–478 | Cite as

Melamine-induced urinary calculi in infants—sonographic manifestations and outcomes 1 year after exposure

Original Article



In 2008, the melamine-tainted-milk incident started with reports of increased incidence of urolithiasis in infants in China. Affected children were screened for urolithiasis.


The purpose of this study was to analyze sonographic characterization of infant melamine-induced urolithiasis.

Materials and methods

Transabdominal US examination was done in 603 infants with melamine-induced calculi. The imaging characteristics of calculi and hydronephrosis were analyzed. Follow-up US imaging was performed.


Comet-tail sign was seen behind the calculus of <4 mm. Calculi of ≥4 mm were found in 299 inpatients with clear posterior border and with or without light shadowing. Solitary and multiple stones had similar incidence. Incidence of calculi in the inferior renal calyx was the highest (55.2%) in inpatients. Calculus size in inpatients age 2–3 years was smaller than that of children younger than 2 years old (P < 0.05). Inpatients age 2–3 years had the highest incidence rate (48.0%) of hydronephrosis.


Calculi of <4 mm manifested as hyperechoic foci near the renal papillae, while calculi of ≥4 mm usually manifested as echogenic foci with visible inferior edge in the renal calyx. Hydronephrosis was a common imaging finding in inpatients ages 2–3 years.


Urolithiasis Melamine US Infants 


  1. 1.
    World Health Organization (2008) Melamine and cyanuric acid: toxicity, preliminary risk assessment and guidance on levels in food. WHO, GenevaGoogle Scholar
  2. 2.
    Langman CB, Alon U, Ingelfinger J et al (2009) A position statement on kidney disease from powdered infant formula-based melamine exposure in Chinese infants. Pediatr Nephrol 24:1263–1266PubMedCrossRefGoogle Scholar
  3. 3.
    Guan N, Fan Q, Ding J et al (2009) Melamine-contaminated powdered formula and urolithiasis in young children. N Engl J Med 360:1067–1074PubMedCrossRefGoogle Scholar
  4. 4.
    Yu H, Guo-Ping J, Lei Z et al (2009) Ultrasonographic characteristics of urolithiasis in children exposed to melamine-tainted powdered formula. World J Pediatr 5:118–121CrossRefGoogle Scholar
  5. 5.
    Ministry of Health of the People’s Republic of China: medical treatment information of Sanlu melamine-contaminated milk powder. The Chinese Ministry of Health Bulletin. September 11, 2008. [in Chinese] Available at:
  6. 6.
    Kroovand RL (1997) Pediatric urolithiasis. Urol Clin North Am 24:173–184PubMedCrossRefGoogle Scholar
  7. 7.
    Moe OW (2006) Kidney stones: pathophysiology and medical management. Lancet 367:333–344PubMedCrossRefGoogle Scholar
  8. 8.
    Palmer JS, Donaher ER, O’Riordan MA et al (2005) Diagnosis of pediatric urolithiasis: role of ultrasound and computerized tomography. J Urol 174:1413–1416PubMedCrossRefGoogle Scholar
  9. 9.
    Lam HS, Ng PC, Chu WC et al (2008) Renal screening in children after exposure to low dose melamine in Hong Kong: cross sectional study. BMJ 337:a2991PubMedCrossRefGoogle Scholar
  10. 10.
    Wang IJ, Chen PC, Hwang KC (2009) Melamine and nephrolithiasis in children in Taiwan. N Engl J Med 360:1157–1158PubMedCrossRefGoogle Scholar
  11. 11.
    Puschner B, Poppenga RH, Lowenstine LJ et al (2007) Assessment of melamine and cyanuric acid toxicity in cats. J Vet Diagn Invest 19:616–624PubMedCrossRefGoogle Scholar
  12. 12.
    Ministry of Health of the People’s Republic of China: medical treatment of infants affected by Sanlu melamine-contaminated milk powder. The Chinese Ministry of Health Bulletin. October 15, 2008. [in Chinese]Google Scholar
  13. 13.
    Coe FL, Evan A, Worcester E (2005) Kidney stone disease. J Clin Invest 115:2598–2608PubMedCrossRefGoogle Scholar
  14. 14.
    Lau HY, Wong CS, Ma JK et al (2009) US findings of melamine-related renal disorders in Hong Kong children. Pediatr Radiol 39:1188–1193PubMedCrossRefGoogle Scholar
  15. 15.
    Ren FY, Wang Y, Hou XB et al (2009) Clinical and imaging features in 16 infants exposed to food contaminated with melamine and cyanuric acid. AJR 192:707–710PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Fang Nie
    • 1
  • Xin-jie Li
    • 1
  • Pan-feng Shang
    • 2
  • Ying Wang
    • 3
  1. 1.Department of Medical UltrasonicsThe Second Hospital of LanZhou UniversityLanZhouPeople’s Republic of China
  2. 2.Department of Urology SurgeryThe Second Hospital of LanZhou UniversityLanZhouPeople’s Republic of China
  3. 3.Department of Medical UltrasonicsThe First Affiliated Hospital of GuangZhou Medical CollegeGuangzhouPeople’s Republic of China

Personalised recommendations