RESUMEN
Background:The dimension and function of kidney have close relationship. In the developing countries, the index on kidney dimension of children has rather fully studied. In Viet Nam, most of studies only conducted on adults. Objectives:This study aims to determine the ultrasound kidney dimension and the correlation of kidney length and age, weight and height of children aged from 6 to 8 years old. Subjects and method: The data was obtained from a prospective study on 180 normal children at age from 6 to 8 years. Each kidney was measured length, width , thickness, and parenchymal thickness, and the mean values were recorded. The relationship of kidney length with age, body weight, body height were also taken. Results: Kidney dimension was increased by age. The average ultrasound kidney dimension:+ Right kidney: At 6 years old: Boy: length: 72.8\xb14; width: 31.2\xb13 ; thickness: 33.9\xb12 ; Girl: length: 69.8\xb15; width: 30.4\xb12 ; thickness: 32.7\xb12. At 7 years old: Boy: length: 75.2\xb14; width: 31.9\xb12; thickness: 33.8\xb13; Girl: length: 75.8\xb15; width: 32.0\xb12; thickness: 32.9\xb14; + Left kidney: At 6 years old: Boy: length: 73.9\xb15; width: 33.7\xb13 ; thickness: 34.9\xb12 ; Girl: length: 71.1\xb14; width: 32.4\xb13 ; thickness: 32.4\xb16. At 7 years old: Boy: length: 77.7\xb13; width: 33.8\xb13 ; thickness:34.7\xb12; Girl: length: 76.9\xb17; width: 32.0\xb12; thickness: 33,9\xb15; The kidney length, kidney weight, kidney volume of boys were bigger than girls, and the difference was significant (p<0.05). Conclusion: The kidney length correlated strongly and positively with body weight, body height and age.