ABSTRACT
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.
ABSTRACT
Objective To study the effect of heterogeneity in different parts of acute and chronic deep venous thrombus on the ultrasound shear wave elasticity value.Methods Fifteen Japanese rabbits were used to create an inferior vena cava (IVC) thrombus model via IVC ligation.Young's modulus of the thrombus head,body and tail were measured using ultrasonic shear wave elasticity technique on the fifth day (acute phase) and 14th day (chronic phase) of thrombus formation.Pathological sections were obtained from the IVC thrombus in five rabbits at the two points of time mentioned above.Pair t-test and one-way analysis of variance (ANOVA) were used to compare the data between groups.Results On the fifth day,Young's modulus values of the thrombus head,body and tail were (5.73 ±0.47)kPa,(7.82±0.63)kPa and (4.76±0.45)kPa respectively.ANOVA showed significant difference among three parts (F=134.468,P ＜ 0.01).The value of the thrombus body was significantly higher than that of the head and tail (both P ＜ 0.01),and the value of the head was significantly higher than that of the tail (P ＜ 0.01).On the 14th day,Young's modulus values of the thrombus head,body and tail were (12.46 ± 2.59)kPa,(15.08 ±2.71)kPa and (10.03 ± 2.02)kPa,respectively.ANOVA analysis also showed significant difference among three parts (F=10.539,P ＜ 0.01).The value of the thrombus body was significantly higher than that of the tail (P ＜ 0.01),and also higher than that of the head,although the difference was not significant (P ＞ 0.05).There was no significant difference between the head and tail (P ＞ 0.05).Young's modulus values of the thrombus head,body and tail in the chronic phase were significantly higher than those in the acute phase (t=-7.456,-7.989 and-8.159,respectively,all P ＜ 0.01).Pathological results showed that there was significant difference in thrombus structure and composition among different parts of the thrombus and among the thrombi in different individuals at corresponding points of time following thrombus formation.Conclusion There is significant heterogeneity among different parts of the same thrombus and among different thrombi at corresponding points of time after thrombus formation.Continual monitoring of the thrombus with ultrasound elasticity imaging may help to improve the accuracy of thrombosis staging.
ABSTRACT
Objective To study the changes of Young's modulus value of the renal cortex,vertebral body and sinus when there was a different degree of acute renal artery stenosis.Methods 10 Japanese white rabbits were used for this study.The left renal artery was dissected.An ultrasound probe was placed on the left kidney,Young's modulus of the renal cortex,vertebral body and sinus were recorded using shear wave ultrasound elastic imaging technique during three stages:when the renal artery was intact (0％ stenosis),tied with a suture (＞ 50％ stenosis),and ligated (100％ stenosis).Renal tissue elasticity with different degrees of renal artery stenosis were compared.Pathological study was carried out in the kidneys,each with either 0％,＞ 50％ or 100％ renal artery stenosis.Results The mean values of Young's modulus from the renal cortex,vertebral body and sinus with different degrees of renal artery stenosis were as follows:0％ stenosis,(16.31 ±1.70) kPa,(13.38± 1.63) kPa,and (12.75±2.26) kPa;＞ 50％ stenosis,(14.16±2.34) kPa,(11.49±2.70) kPa,and (10.72±2.56) kPa;100％ stenosis,(11.35 ± 1.48) kPa,(8.39± 1.29) kPa,and (7.08 ± 1.52) kPa.The mean value of Young's modulus from the renal cortex was significantly higher than those from the renal vertebral body and sinus (P ＜ 0.05).The mean values of Young's modulus from different parts of the kidney decreased progressively with an increase in renal artery stenosis (P ＜ 0.05).The pathological study demonstrated that with the increase in the severity of renal artery stenosis,glomerular volume,renal interstitial capillary diameter and red blood cells decreased.When renal artery stenosis reached 100％,there was patch degeneration and inflammatory cell infiltration within the renal interstitium,and mild degeneration of tubular epithelial cells with obscure cell borders.Conclusions The value of Young's modulus from the renal cortex was higher than those from the renal pyramid and sinus in rabbits.The values of Young's modulus from the renal cortex,pyramid and sinus decreased with an increase in the severity of renal artery stenosis,which suggest that,in the study of the elasticity of the kidney,the renal artery blood flow dynamic state can obviously affect the value of the elasticity of the kidney.