Exprimental Study On Quantitative Analysis Of Early Arascular Necrosis Of Femoral Head In Rabbits By Contrast-enhanced Ultrasound

Objective1.Comparing the differences between the femoral head of healthy rabbits and early femoral head necrosis rabbits by conventional two-dimensional ultrasound2.Use contrast-enhanced ultrasound(CEUS)to examine the perfusion of the femoral head in healthy rabbits and those with early femoral head necrosis.To analyze the value of CEUS in evaluating the perfusion of femoral head surface in rabbits with early femoral head necrosis with the quantitative parameter and the pathology results.Methods1.20 New Zealand white rabbits were randomly divided into blank group(8)and model group(12).To use endotoxin(LPS)combined with glucocorticoid to establish the early femoral head necrosis model in rabbits.2.Colour doppler ultrasound was used to observe the femoral head of rabbits at different periods in the blank group,the 3-week model group and the 5-week model group.Compare the differences on the colour doppler ultrasound images between these three groups.3.To use contrast-enhanced ultrasound to examine the blood perfusion on the surface of the femoral head in the blank group,the 3-week model group and the 5-week model group and acquire the Time-Intensity Curve(TIC).By analyzing the TIC,we can gain these parameters,peak enhancement(El),time to peak(TTP),enhanced slope(AS),attenuation slope(DS),mean transit time(mTT)and compare whether there have statistical differences among the parameters.To analyze the value of contrast-enhanced ultrasound in evaluating the surface blood perfusion of the femoral head in early femoral head necrosis rabbits.4.Compare the blank group,the 3-week model groups and the 5-week model groups of pathological results of the rabbit femoral head,through the analysis of three groups in different periods of rabbit femoral head after HE staining the pathological morphology of stage,statistical analysis of microvascular count and empty pit rate,and ultrasonic imaging parameters,To verify the authenticity of CEUS in evaluating the perfusion value of femoral head surface blood flow in early femoral head necrosis rabbits.Results1.There was no significant difference between the blank groups and the model groups in morphological structure and colour doppler ultrasound images.2.CEUS quantitative analysis showed that blank group compared to the 3-weeks model group,the El was markedly increased and was statistically significant(P=0.01,P<0.05).There were no significant statistical differences on AS,DS,mTT and TTP between the two groups(AS:P=0.21,P>0.05;DS:P=0.29,P>0.05;mTT:P=0.98,P>0.05;TTP:P=0.44,P>0.05).The AS,DS,mTT and TTP were statistically different between the 5-week model group and the blank control group(AS:P=0.02,P<0.05;DS:P=0.03,P<0.05;mTT:P=0.00,P<0.05;TTP:P=0.01,P<0.05),while El had no significant statistical(P=0.21,P>0.05).3.Histopathological results showed that no abnormal changes were found in the histological examination of the blank control group.In 6 cases(12 head of femurs)of 3-week model groups,there were 2 femoral heads of osteonecrosis pathological period ?.The rest of the pathologic stage belonged to period? before.In 6 cases(12 head of femurs)of 5-week model groups,the pathologic stage belonged to period ? before.The results of percentage of empty lacunae showed that 3-week model groups are higher than 5-week model groups and have statistical difference(P=0.00,P<0.05).The results of microvessel count(MVD)showed that the number of microvessels in the two model groups was lower than that in the blank group,and the difference was statistically significant(P=0.00,P<0.05).The MVD between the two model groups also have statistical difference(P=0.04,P<0.05).4.Correlation analysis of all parameters between MVD and CEUS showed a weak positive correlation between MVD and DS(r=0.36,P=0.02,P<0.05),MVD and El showed a weak negative correlation(r=-0.39,P=0.01,P<0.05),MVD and AS(P=0.24,P>0.05),mTT(P=0.32,P>0.05),TTP(P=0.65,P>0.05)have no correlation.Conclusion1.The femoral head necrosis in the 3-week model group and 5-week model group is difficult to be distinguished from normal femoral head by ordinary two-dimensional ultrasound images.2.CEUS is a safe,simple and cheap method for detecting early femoral head necrosis compared with MRI and radionuclide scan.CEUS can reflect the distribution of micro blood vessels on the surface of femoral head to some extent.The most important is,the AS,DS,mTT and TTP of the necrotic femoral head in the 5-week model group were significantly decreased compared with the blank group by TIC.It indicated that the effective perfusion time of blood flow in the femoral head of early necrosis decreased.3.The histopathology of femoral head necrosis in the 3-week model group and 5-week model group all showed significant reduction of MVD.This change was consistent with the results of CEUS.However,pathological changes such as blood biochemical changes and vascular elasticity may occur before MVD changes.