Comparative Study Of Contrast-enhanced Ultrasound Imaging And Histopathologic Findings In Mice Ca761/L Breast Tumor Models

ObjectiveTo observe the varied contrast-enhanced ultrasound (CEUS) imaging appearance of breast tumors compared with histopathologich findings in mice Ca761/L breast tumor models.Methods1、Breast tumor cells (Ca761/L) were implanted into the left thigh of24mice to set up animal models.2、Ultrasound examination were performed in3～6mice randomly selected every day from2to12days after implantation to observe breast tumorigenesis and angiogenesis continuously. Measure the tumor size and analyze the imaging of ultrasound. After CEUS examination,1-3mice were put to death and the remnant underwent experiment the next day.3、To take the breast tissue HE and CD34stained and count the number of MVD.Results1、Rate of tumor were100%in24mice. Among them, a total of46cases of ultrasound examination had been performed in23mice from2to12days after implantation except one died of anesthetic accident.2、Ca761/L breast tumor cells growed fast in vivo. The grow curve was flat during the2～6days after implantation, and rose sharply during the7～9days after implantation, and then the rate of increase decreased gradually during the10～12days after implantation. So, the slope of the curve reflected the growth rate of tumor in different stages.3、The patterns of enhance included four types:Type Ⅰ, peripheral enhance,15cases(32.6%,15/46); Type Ⅱ, peripheral enhance with mild penetration,8cases (17.4%,8/46); Type III, most areas of the tumor enhanced,11cases (23.9%,11/46); Type IV, peripheral enhance with focal nodular enhance inside the tumor,12cases(26.1%,12/46).4、Ultrasound image feature in different size group. In group1(2～6days after implantation), all the tumor presented as homogeneous solid mass and no color signals can be detected, but enhancement were found in CEUS. They can be presented as enhance pattern of Type I (70%,14/2), Type II (20%,4/2) and Type III (10%,2/20), but mainly presented as Type I (70%). In group2(7～9days after implantation), the echotexture of the mass changed from homogeneous(100%) to heterogeneous(26.7%,4/15) in grey-sale imaging; from no color signals (100%,20/20) to colorful signals (46.7%,7/15) in CDFI; the enhance pattern mainly presented as Type Ⅲ(53.3%,8/15). In group3(10-12days after implantation), the mass were almost heterogeneous(81.8%,9/11), and rich color signals can be detected (100%,11/11), and all the tumor presented as enhance pattern of Type Ⅳ.5、No correlation was found between MVD and tumor volume (P>0.05), but MVD per cubic centimeter negatively correlated with tumor volumes (r=-0.576, P=0.004).6、The mean value of MVD was not significant difference (P>0.05) in different enhance patterns, but enhance patterns(Type I to IV) negatively correlated with MVD per cubic centimeter (r=-0.87, P<0.01).7、Contrast enhanced area corresponded to high degree cellularity. Non enhanced area corresponded to necrosis with or without low degree cellularity or inflammatory cells.Conclusions1、CEUS could detect tumor angiogenesis earlier than ultrasound which provided foundation for early diagnosis of breast cancer.2、The enhance patterns reflected the features of vasculature during tumor rapid growth and are correlated with histologic features.3、The enhance patterns of CEUS could reflect the number of MVD per cubic centimeter inside the tumor.