1·Objective: to form formulas to calculate the pressure difference between left renal rein and inferior vena cava and test the value of this pressure difference in the diagnosis of Nut Cracker Syndrome.
目的：构建计算左肾静脉与下腔静脉之间压差的方程序，并检验其在胡桃夹综合症诊断中的价值。
2·Objective and Methods to research into the diagnostic significance and clinical value of CDU on nut-cracker phenomenon.
目的和方法探讨彩超对胡桃夹现象的诊断意义及临床价值。