Objective To observe the ultrastructure changes of brain of the late trimester of fetal rats via transumbilical vein injection using contrast-enhanced ultrasonography.Methods The forty pregnant rats in the late trimester were divided into four experimental groups randomly.After being successfully punctured in the umbilical vein,two fetus was randomly chosen from maternal uterus with injection contrast agent SonoVue or normal saline solution(20 fetus/each group).Group A as control group with injection of normal saline solution(120 μl/kg);group B as low dose group with injection of SonoVue 0.014 mg/kg(120μl/kg,0.118 ng/ml);group C as media dose group with injection of SonoVue 0.14 mg/kg(120 μd/kg,1.18mg/ml)and group D as high dose group with injection of SonoVue 1.4 mg/kg(120 μl/kg,11.8 mg/ml).After observing the process of every contrast-enhanced ultrasonographic examination,tissue slices of brain of these fetus were made for electronmicroscope investigation.Results ①There was no enhancement in the fetus and placenta in group A.Enhancement couldn't be clearly seen in group B because of fast wash-out contrast agent.On the contrary,the fetus and placenta enhancement in turn could be seen in group C and group D.Enhancement never be seen in maternal uterus and uterine outside.②There was no significant difference of ultrastructure changes of the fetal brain tissues in group A and group B with electronmicroscope.Different degree rough endoplasmic reticulum enlargement,mitochondria swelling,endothelial cell injury,glycogen deposition and vacuolization in the brain cells were found in group C and group D,and the value of contrast between the two groups was significantly different(P＜0.05).Conclusions It is decreasd gradually effects to perform transumbilical vein contrast enhanced ultrasonography with reducing gradually dose for the late trimester of fetal rats,but enhancement has been invisible in the low dose group.

Objective To study the application of contrast-enhanced ultrasonography (CEUS) in the evaluation of the stability of carotid atherosclerotic plaque (CAP).Methods 162 patients with CAP were selected as study group.Meanwhile,34 patients with carotid artery strong echo plaques were selected as control group.The color doppler ultrasound was used to observe the CAP.Results The proportions of lipid type,fiber type,calcification and ulcer plaque in the study group were 21.60%,33.33%,34.57% and 10.37%,which were higher than those of the control group (5.88%,2.94%,2.94% and 2.94%),the differences were statistically significant (χ2=4.537,12.859,13.629 and 3.855,all P<0.05).There were 75 patients of soft plaques,36 patients with mixed plaques,51 patients with hard plaque in 162 patients.The new blood vessels classification in soft plaque group (36.00%,45.33% and 10.33%) were higher than the mixed plaque (30.56%,41.67% and 8.33%) and hard plaque group (31.37%,13.72% and 7.84%).The peak intensity (-86.41±7.81) %,tmax (8.34±1.62)s,mean transit time (24.18±8.67)s in the soft plaque group were significantly lower than the mixed plaque [(-100.73±6.52)%,(9.79±2.14)s and (28.93±9.11)s] and hard plaque patients [(-104.14±6.15)%,(10.23±2.33)s and (30.07±9.48)s],the differences were statistically significant (t=9.518,6.966,2.658,13.592,5.374 and 3.064,all P<0.05),but there were no statistically significant differences between mixed plaque and hard plaque (all P>0.05).The plaque diameter (4.13±0.75)mm diagnosed by CEUS was significantly larger than that of conventional ultrasound [(3.62±1.14)mm],the difference was statistically significant (t=4.757,P=0.000).Conclusion The CEUS can qualitatively detect the atherosclerotic plaque angiogenesis,can quantitatively assess plaque,evaluate the stability of the plaques,and the sensitivity is high.