Lei Shuang, Ma Teng, Gao Zeping, Zhang Qi, Wang Shuo, Hu Dehong, Sheng Zonghai, Li Yongchuan, Huang Jiqing, Zhu Benpeng, Zheng Hairong
IEEE Trans Biomed Eng. 2022 Nov;69(11):3438-3448. doi: 10.1109/TBME.2022.3170557. Epub 2022 Oct 19.
The morphological and hemodynamic characterization of the microvascular network around the gastrointestinal (GI) tract can be of significant clinical value for the early diagnosis and treatment of GI tract cancer. Ultrasound localization microscopy (ULM) imaging has been demonstrated to be capable of resolving the microvascular network. However, the endoscopic application of ULM imaging techniques is still unknown. In this study, an endoscopic ultrasound localization microscopy (e-ULM) imaging technique was developed to evaluate the changes of microvasculature during GI tract tumor growth.
A customized circular array transducer (center frequency: 6.8 MHz) and the coherent diverging wave compounding method were used to generate B-mode images. Spatiotemporal singular value decomposition processing was used to eliminate the background signals before signal localizations. The centroids of spatially isolated signals were localized and summed to generate the final super-resolution image.
The final microvasculature map of a rabbit GI tract tumor reveals that e-ULM can be used to surpass the diffraction limit in traditional endoscopic ultrasound (EUS) imaging. Furthermore, it is observed that data from different stages of tumor growth exhibit significant differences in microvascular pattern and density.
Our study demonstrated the implementation and application of an in vivo e-ULM imaging technique for the evaluation of the microvasculature of GI tumors.
The efficient e-ULM imaging technique shows potential for use in the detection of GI tract tumor microcirculation changes and subsequent diagnosis of GI tract cancer.
胃肠道（GI）周围微血管网络的形态学和血流动力学特征对于胃肠道癌的早期诊断和治疗具有重要的临床价值。超声定位显微镜（ULM）成像已被证明能够分辨微血管网络。然而，ULM成像技术在内镜检查中的应用尚不清楚。在本研究中，开发了一种内镜超声定位显微镜（e-ULM）成像技术，以评估胃肠道肿瘤生长过程中微血管系统的变化。
使用定制的圆形阵列换能器（中心频率：6.8 MHz）和相干发散波复合方法生成B模式图像。在信号定位之前，使用时空奇异值分解处理来消除背景信号。对空间上孤立信号的质心进行定位并求和，以生成最终的超分辨率图像。
兔胃肠道肿瘤的最终微血管图谱显示，e-ULM可用于突破传统内镜超声（EUS）成像中的衍射极限。此外，观察到肿瘤生长不同阶段的数据在微血管模式和密度方面存在显著差异。
我们的研究展示了一种用于评估胃肠道肿瘤微血管系统的体内e-ULM成像技术的实施和应用。
高效的e-ULM成像技术在检测胃肠道肿瘤微循环变化及后续胃肠道癌诊断方面显示出应用潜力。
