BACKGROUND: The kidney size is important in differentiating many renal diseases. Some studies have been reported about the normal kidney size in the foreign countries. However, no studies were performed by using ultrasonography in Korea. Therefore, we investigated the normal kidney length, the factors affecting the kidney length and the relationship of each other. METHODS: One thousand three hundred eighty eight healthy Koreans were scanned for the kidney length by ultrasonography and were measured for their body index(height, weight, body surface area, total body water, and fat free mass). We analyzed the association between kidney length and body index. RESULTS: Eight hundred four male and five hundred eighty four female were involved in this study and their mean age was 47.8+/-10.3 in male, 48.1+/-9.5 in female. 1) The average value of left and right kidney was 10.65+/-0.80cm, 10.50+/-0.78cm respectively, and the left kidney was greater than right one(P<0.01). 2) The difference between male and female was 10.77+/-0.79cm, 10.49+/-0.78cm respectively in the left kidney and 10.66+/-0.76cm, 10.27+/-0.75cm in the right kidney(P<0.01). 3) The aging process nearly does not affects the kidney size from 4th decade to 7th decade. However, the kidney size is getting smaller after 8th decade. 4) The correlation coefficient between the kidney size and height, weight, body surface area, total body water, fat free mass was 0.37, 0.41, 0.43, 0.37, 0.38(P<0.01) respectively. CONCLUSION: The kidney length showed normal distribution in normal Korean adult and the length greater than 12.36cm, smaller than 8.76cm means out of its range of normal(+/-2SD) irrespective of sex and position. The body surface area has the largest correlation with kidney size in both sex(r=0.38/0.44; left/right, P<0.01).
Adult* ; Aging ; Body Surface Area ; Body Water ; Body Weight ; Female ; Humans ; Kidney* ; Korea ; Male ; Ultrasonography*