Evaluation of pancreatic microvasculature by contrast-enhanced endosonography with high resolution -application to diagnosis and treatment-

本研究的目的是研制一种具有对比谐波模式的超声内镜，用于2^<和>生成造影剂，并建立利用它观察消化器官微循环的方法。在2003年至2004年期间，我们成功地发明了适合2^<和>生成造影剂的对比谐波模式，并开发了可用于该模式的微凸探针。此外，我们用探针观察了狗的消化器官微循环。2005年，我们通过切除部分胰腺，形成低血管病变，制作胰腺癌动物模型，观察病变血管的分布情况。这些结果提示了观察胰腺癌微循环的可能性。我们还评估了对比增强谐波超声的临床意义。通过我们的研究，我们认为超声造影有助于胰腺癌的诊断（Gut 2004,53,854 -859），评估胰腺癌对化疗的反应（J Gastroenterol 2006 in press），以及评估胃肠道间质瘤的恶性潜能（J Gastroenterol 2005,40,247 -255）。我们报道了当采用B模式时，内镜引导乳糜丛神经松解术需要计算机断层扫描（消化内镜，2006,in press）。由于2^<和>代造影剂未被允许在日本使用，我们在德国Bethesda综合医院进行了对比增强谐波超声的临床试验，其中2^<和>代造影剂之一SonoVue被允许用于临床。17例行超声造影检查。它可以显示胰腺和胃肠道间质肿瘤的实质图像，这是以前的超声检查无法描绘的。这一结果表明，对比增强超声可用于临床目的。

The purposes of the present study were developing an echoendoscope equipped with contrast-harmonic mode for 2^<nd> generation of contrast agents and establishing the method to observe microcirculation of digestive organs by means of it. During the period from 2003 to 2004, we succeeded to invent contrast-harmonic mode that is suite for 2^<nd> generation of contrast agents and to develop a microconvex probe available for the mode. Furthermore, we observed microcirculation of digestive organs in dogs with the probe. In 2005, we made an animal model of pancreatic carcinomas by ablating a part of the pancreas, which resulted in a hypovascular lesion, and observed the vascularity of the lesion. Those results suggested the possibility to observe microcirculation of pancreatic carcinomas. We also evaluated the clinical significance of the contrast-enhanced harmonic ultrasonography. Through our studies, it was suggested that the contrast-enhanced ultrasonography is useful for depicting pancreatic carcinomas (Gut 2004, 53, 854-859), evaluating the response of pancreatic carcinomas to chemotherapy (J Gastroenterol 2006 in press) and estimating the malignant potential of gastrointestinal stromal tumors (J Gastroenterol 2005, 40, 247-255). We reported that endosonography guided celiac plexus neurolysis required computed tomography when B mode was employed (Digestive Endoscopy 2006, in press). Because the 2^<nd> generation of contrast agents have not been permitted to use in Japan, we performed the clinical trial of contrast-enhanced harmonic endosonography at Bethesda general hospital in Germany where one of 2^<nd> generation of contrast agents, SonoVue, were permitted for clinical use. The contrast-enhanced endosonography was performed in 17 cases. It visualized the parenchymal images of pancreatic and gastrointestinal stromal tumors that previous endosonography failed to depict. This result demonstrated that contrast-enhanced endosonography was available for clinical purpose.