Objective:To investigate the clinical characteristics of urinary system abnormalities in Chongqing and its surrounding area

and to assess the role of the large-scale urinary system ultrasound screening in the asymptomatic children with kidney and urinary tract abnormalities. Methods:We performed urinary system ultrasound on Screening 14 256 children from September 2008 to October 2008 in Chongqing Children’s Hospital. The total samples were allocated into five groups as follows:less than 1 year group;1 to 3 years group;3 to 5 years group;5 to 10 years group ;more than 10 years group. Then according to each group’s age

sex

disease location

severity difference

we performed statistical analysis. Results:409(2.87%)of 14 256 children had abnormalities

284 of whom was diagnosed with significant anomalies

including hydronephrosis

renal maldevepment (aplastic

dysplastic

hypoplastic

ectopic kidneys)and renal agensis

nephrolithiasis

simple renal cyst

multicystic dysplastic kidneys (MCKD)

ureter dilation

duplex kidneys and so on. Among these anomalies

the most prevalent abnormal finding was hydronephrosis accounting for 130 cases

almost a half of 284 (45.77%)

92 cases in males

38 cases in femal. The prevalence of melamine related urinary calculus was as 5.17 times as that of others and its 95% confidence interval(CI)of population relative risk was [3.28

8.14]. Conclusion:① Ultrasonography in the diagnosis of diseases of the urinary system can play an important role

especially for congenial anomalies of kidney and urinary tract(CAKUT)and /or hydronephrosis and so on. Therefore

an early diagnosis of these defects allows to realize as fast as possible the best medical and/or surgical treatment

preventing or at least slowing down the progression to chronic renal failure. ② The prevalence rate of hydronephrosis in male is higher than female. ③Exposure to melamine- contaminated formula is associated with urinary stones.