Oezdemir Ipek, Li Junjie, Song Jane, Hoyt Kenneth
Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA.
IEEE Int Ultrason Symp. 2021 Sep;2021. doi: 10.1109/IUS52206.2021.9593426. Epub 2021 Nov 12.
The purpose of this research project was to evaluate the use of 3-dimensional (3-D) super-resolution ultrasound (SR-US) imaging to assess any early changes in breast cancer after treatment with a vascular-disrupting agent (VDA). A Vevo 3100 ultrasound system (FUJIFILM VisualSonics Inc) equipped with an MX 201 transducer was used for image acquisition. A total of 2.5 × 10 microbubbles (MBs) were injected into the tail vein of anesthetized breast cancer-bearing mice using repeat bolus injections every 5 min. A total of 10 stacks of ultrasound images were collected as the transducer was mechanically moved across the tumor at 0.6 mm intervals yielding a 6-mm thick volume. At each tumor location, a stack contained 1 × 10 frames of ultrasound data that were acquired at 463 frames/sec and stored as in-phase/quadrature (IQ) format. After motion correction, each temporal stack of ultrasound images was processed separately for clutter signal removal, which was followed by MB localization and enumeration before generation of the final SR-US image. After reconstruction of the 3-D SR-US volume dataset, the tumor microvasculature was enhanced using a multiscale vessel enhancement filter. Vessels from the resultant microvascular network were then segmented using an adaptive thresholding method. Finally, mean microvascular density (MVD) measurements from each tumor volume were computed as a summarizing statistic. While no differences were found between baseline SR-US image-derived measures of MVD ( = 0.76), these same measurements were significantly lower at 24 h after VDA treatment ( < 0.001). Overall, 3-D SR-US imaging detected early tumor changes following treatment with a vascular-targeted drug.
本研究项目的目的是评估使用三维（3-D）超分辨率超声（SR-US）成像来评估血管破坏剂（VDA）治疗后乳腺癌的任何早期变化。使用配备MX 201换能器的Vevo 3100超声系统（富士胶片VisualSonics公司）进行图像采集。每隔5分钟重复推注，将总共2.5×10个微泡（MBs）注入麻醉的荷乳腺癌小鼠的尾静脉。当换能器以0.6毫米的间隔在肿瘤上机械移动时，总共收集10组超声图像，产生一个6毫米厚的体积。在每个肿瘤位置，一组包含1×10帧超声数据，这些数据以463帧/秒的速度采集，并存储为同相/正交（IQ）格式。在进行运动校正后，对每组超声图像的时间序列分别进行处理以去除杂波信号，然后在生成最终的SR-US图像之前进行MB定位和计数。在重建3-D SR-US体积数据集后，使用多尺度血管增强滤波器增强肿瘤微血管。然后使用自适应阈值方法对所得微血管网络中的血管进行分割。最后，计算每个肿瘤体积的平均微血管密度（MVD）测量值作为汇总统计量。虽然在基线SR-US图像得出的MVD测量值之间未发现差异（=0.76），但在VDA治疗后24小时，这些相同的测量值显著降低（<0.001）。总体而言，3-D SR-US成像检测到血管靶向药物治疗后肿瘤的早期变化。
