A new renal depth calculating equation for precision evaluate glomerular filtration rate based on the potential living kidney donors CTA detection

Objectives To precision evaluate renal GFR, a new renal depth calculating equation based on the potential living kidney donors CTA detection was developed and was compared it with the other published formulas used in clinic.

Methods The renal depth were measured for 167 living kidney transplant donors by CT scanning, and regression equation of renal depth based on sex, age, height, weight and BMI were derived. The renal depth analysis of other 271 living donors obtained by the regression equation,and were compared with Tønnesen, Taylor, Itoh, T.itoh, Li qian and Inoue equation.

Results ①regression equation: male (female) left renal depth(cm)=0.083×W-0.058H+11.541(10.890) and right renal depth(cm)=13.498×W/H+2.141(1.816), where weight is in kilograms and height is in centimeters.②Both of renal depths renal depths derived by Tønnesen formula were significantly lower than that of this shudy, measured by CT, and formulas which based on CT scanning were no significant difference. ③The correlation coefficient of left/right renal depth in 271 living donors between Tønnesen, Taylor, Itoh, Li qian, Inoue equation and this study is 0.864/0.893,0.937/0.970,0.937/0.970,0.927/0.951,0.937/0.970, respectively.

Conclusions The new equation provide a more precision method to estimating the renal depth than Tønnesene quations, which may improve the GFR measured by Gates and has no racial difference between the westerners and Asians.