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

Abstract

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 wash-out 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 foci 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 microvessels in tumor focus are also keystone factors when tumors are assessed by means of imaging. Key words: Ultrasonography;  Microbubbles; Breast neoplasms;  Hemodynamic phenomena