超声造影定量分析对乳腺良恶性肿瘤血流灌注异质性的评价

Study on the hemodynamic changes in benign and malignant breast tumors by ultrasound contrast quantitative analysis

目的探讨乳腺良恶性肿瘤的血流灌注特征。方法应用实时灰阶超声造影时间-强度曲线定量分析技术检测瘤灶边缘及中心部区域灌注参数及平均灌注参数峰值强度、曲线下面积、达峰时间、廓清时间，光、电镜观察瘤内新生血管显微结构及超微结构改变。结果恶性组时间-强度曲线形态多数（87．88％，29／33）呈速升缓降型，良性组多数（80．00％，27／34）呈缓升速降型。恶性组平均曲线下面积、廓清时间大于良性组，差异有统计学意义（P〈0．05），平均峰值强度、达峰时间两组比较差异无统计学意义（P〉0．05）。恶性组病灶边缘各灌注参数与中心区域相比差异有统计学意义（P〈0．05），良性组病灶边缘各灌注参数与中心区域相比差异无统计学意义（P〉0．05）。光镜下恶性组90．91％（30／33）见坏死灶，问质中见弥漫分布粗细不均的新生血管，血管丰富区位于癌巢边缘，异常扩张的大血管和裂隙状的新生血管并存。良性组均未见坏死灶，血管管径和分布均一。电镜下恶性组新生血管内皮细胞超微结构具有不同于正常血管内皮细胞的分裂旺盛的特征，癌灶边缘以扩张、迂曲的大血管为多，癌灶中心常见狭窄、闭塞的幼稚新生血管及固缩、变形的内皮细胞、周细胞。结论实时超声造影灌注曲线形态、各灌注指标及不同灌注区域灌注指标的差异为乳腺良恶性肿瘤的鉴别诊断提供了重要依据。肿瘤间质中新生微血管密度、形态、分布、结构及功能的差异性是影像学评价肿瘤血管生成的基础。

Objective To compare the differences in histological morphology and hemodynamics between benign and malignant tumor, as well as differences between the different perfusional regions in tumors of the same type. Methods Thirty cases with malignant breast carcinoma and 30 cases with fibroadenoma were inspected by contrast enhanced ultrasound with time-intensity quantitive analysis. Perfusion index like peak intensity（PI） ,area under the curve（AUC） ,time to peak（TTP） and washout time （WOT） were collected both inside and at the margin of focus. The ultrastructures of new microvessesl were observed routinely with microscopy and transmission electron microscopy. Results The curve of malignant tumor group was characterized as ascend rapidly and drop slowly while the benign group presented as ascend slowly and drop rapidly. The AUC and WOT of malignant tumor group were significantly higher than that of benign group,while the PI and TTP had no statistical difference. In malignant tumor group,PI,AUC and WOT of the margin of focus were significantly higher than that of inside region of focus,while TTP was the opposite. However, there was no statistical differences between the perfusion parameter inside and outside of focus in benign group. The ultrastructures of newly built blood vessels in malignant group had strong ability to split,which was different from normal endothelium cells but was similar to other tumor foci. The margin of loci were characterized with dilatating and distorting vessels,and the center of the foci were occupied by narrow,occlusive new vessels and contracted anamorphic endothelium cells and pericytes. Rich microvessel areas located in the margin of foci. Conclusions The perfusion pattern, modality of time-intensity curve,mean perfusion parameter and variance of regional perfusion parameters are valuable diagnostic basis in discriminating benign and malignant breast tumor. The density, modality, distribution, structure and function of new mierovessels in tumor focus are also keystone factors when tumors are assessed by means of imaging.