肾脏中部及下极皮质杨氏模量值差异的动物实验研究

Difference of the values of Young′s modulus between the middle part and inferior extremity of renal cortex: an animal study

目的研究兔肾脏中部与下极皮质杨氏模量值差异。方法 10只日本大耳白兔,结扎肾静脉,结扎前、结扎后15 min、30 min、60 min、90 min,超声剪切波弹性成像技术检测肾脏中部及下极皮质杨氏模量值。采用独立样本t检验,比较同一时间点肾中部与肾下极杨氏模量值之间的差异;采用单因素方差分析方法,比较同一部位不同时间点杨氏模量值之间的差异。结果结扎肾静脉前,肾中部、下极皮质杨氏模量值分别为(15.93±1.70)k Pa、(4.66±1.4)k Pa,结扎后15 min分别为(34.84±4.91)k Pa、(10.95±3.09)k Pa,30 min分别为(41.55±3.19)k Pa、(20.39±4.06)k Pa,60 min分别为(50.63±2.73)k Pa、(30.96±4.98)k Pa;90 min分别为(56.61±2.96)k Pa、(42.40±5.79)k Pa。结扎肾静脉前后,肾中部皮质杨氏模量值均显著高于肾下极,差异有统计学意义(t=21.63、7.44、7.19、5.26、2.41,P均<0.05),结扎后各时点两部位的杨氏模量值均显著高于结扎前(t=-3.30、3.38、-2.47、1.83,P均<0.05),且随时间延长逐渐增加(t=-5.31、8.26、-7.81、3.65,P均<0.05)。结论超声剪切波弹性成像技术测量的兔肾中部皮质杨氏模量值高于肾下极,提示兔肾脏皮质存在各向异性。结扎兔肾静脉后90 min内,肾脏中部皮质杨氏模量值也高于下极。

Objective To study the difference of the values of Young＇s modulus between the middle part and the inferior extremity of rabbit renal cortex. Methods Ten Japanese white rabbits were used for this study. The right renal vein was ligated. At time intervals of 15, 30, 60 and 90 minutes after ligation, the values of Young＇s modulus from different parts of the right renal cortex were recorded. Independent sample t test was used to compare the difference of the values of Young＇s modulus from the middle part and the inferior extremity of renal cortex at the same time point. Single factor variance analysis was used to compare the values of Young＇s modulus at the same point at difference time. Results Before renal vein ligation, the values of Young＇s modulus from the middle part and the inferior extremity of renal cortex were （15.93±1.70） kPa and （4.66±1.4） kPa. After the ligation, the values from those two parts of the kidney were as follows： 15 min after ligation, （34.84±4.91） kPa and （10.95±3.09） kPa; 30 min after ligation, （41.55±3.19） kPa and （20.39±4.06） kPa; 60 min after ligation, （50.63±2.73） kPa and （30.96±4.98） kPa; 90 min after ligation, （56.61±2.96） kPa and （42.40±5.79） kPa. The value of Young＇s modulus from the middle part of renal cortex was significantly higher than the inferior extremity of renal cortex, and the difference was statistically significant （t=21.63, 7.44, 7.19, 5.26 and 2.41, all P〈0.05）. The values of Young＇s modulus from different parts of the renal cortex after renal vein ligation were significantly higher than those before the ligation （t=-3.30, 3.38, -2.47, 1.83, all P〈0.05）, and the values increased gradually with time increased after ligation （t=-5.31, 8.26, -7.81, 3.65, all P〈0.05）. Conclusions The values of Young＇s modulus from the middle part of renal cortex were higher than those of the inferior extremity of renal cortex determined by shear wave ultrasound elastic imaging technique. It is suggested that there is anisotropy in the renal cortex of rabbit. Prior to and within 90 min following renal vein ligation, the values of Young＇s modulus from the middle part of renal cortex were higher than those of the inferior extremity of renal cortex determined by shear wave ultrasound elastic imaging technique.