Comparative Study Of The Different Prediction Formula Of Renal Depth By Renal Dynamic Imaging

Objectives: To obtain the renal depth prediction formula of Chinese people in Liaoning province in renal dynamic imaging,then compare with the Tonnesen formula and Lee formula in the accuracy and applicability.Methods: A total of 292 cases were collected retrospectively from the patients who determined glomerular filtration rate(GFR)by using renal dynamic imaging Gates formula and undertook abdomen CT scanning from November,2016 to January,2018,and their sex,age,abdominal circumference(AC),height and weight were recorded.Patients with ascites,single kidney,hydronephrosis,or intrarenal space occupying lesions,which affect the depth of the kidney,are excluded.Kidney depth was determined by measuring the depth from the skin to the anterior and posterior surfaces of the kidney at the renal hilum and then the average of these values were taken as the kidney depth.The relations between kidney depth and several different anthropometric variables were determined by using a multiple linear stepwise regression analysis in order to develop a new regression equation for estimating right and left kidney depth.The 292 cases were divided into two groups randomly,of which one group(175 cases)was used to derive a regression equation as a generation group,and another group(117 cases)was used to verify the formula as a validation group,then compared the difference between the two groups of general data.With the kidney depth of CT as the evaluation standard,the new depth of the new formula from the generation group,Lee formula and Tonnesen formula were compared with the kidney depth of CT by applying one way ANOVA used to analyze the difference and by ICC used to compare the correlation and the formula of more higher accuracy of kidney depth in Liaoning province were obtained.Results: There were statistical significance of kidney depths among the cases of different age,height(m),weight(kg),and AC(cm),and the new formula from the generation group were as followed: left kidney depth(cm)=3.885 + 0.011 × age-2.450 × height +0.067 × weight + 0.026 × AC,right kidney depth(cm)= 4.474-2.136 × height + 0.060× weight + 0.029 × AC(height: m weight: kg AC: cm).The results showed that the depth of left and right kidney kidneys calculated by the new formula was compared with the depth of CT,the difference between the left kidney and the right kidneys was not statistically significant(P>0.05).The renal depth of Tonnesen formula and Lee formula was compared with the depth of CT,and the difference was significant statistically significant(P<0.001).The correlation of the left and right kidney kidney depth in the new formula is better than that of the Tonnesen formula and the Lee formula.the formula were more accurate than the Tonnesen formula and Lee formula.Conclusions: In this study,with the kidney depth of CT as the evaluation standard,the new formula was obtained for the Chinese people in Liaoning province in kidney dynamic imaging.After verification,the accuracy of the new formula is better than the Tonnesen formula and Lee formula of the present application.