Norton I D, Bruce C J, Seward J B, Vazquez-Sequeiros E, Affi A, Wiersema M J
Divisions of Gastroenterology and Cardiology, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
Gastrointest Endosc. 2001 Apr;53(4):496-9. doi: 10.1067/mge.2001.113280.
EUS requires a significant capital outlay. The ability to perform high-resolution phased array scanning and Doppler interrogation by using a catheter that interfaces with a standard US console could increase the accessibility of EUS. Recently, an electronic phased-array US catheter was developed for intracardiac use. To date, this technology has not been applied to the GI tract. The aim of this study is to determine the feasibility and imaging characteristics of a new phased array scanning US catheter in the GI tract.
Swine were placed under general anesthesia. This study used a 100 cm, 10F, torquable catheter with 4-way tip deflection to greater than 90 degrees. The catheter tip houses a phased vector array transducer with variable frequency (5.5-10 MHz) and variable focal distance. It has pulsed/color and power Doppler capability. The probe was passed through a therapeutic flexible sigmoidoscope into the upper GI tract. Acoustic coupling was achieved via a condom filled with water or by gastric water infusion. Needle visualization experiments were performed with a second endoscope (also passed per oral) with a standard EUS-guided fine needle aspiration needle.
Acoustic coupling was easily achieved. Resolution of the GI wall into characteristic layers (esophagus 5, stomach 7) was demonstrated. At 5.5 MHz, tissue resolution and Doppler imaging were excellent to greater than 10 cm from the transducer. A 22-gauge EUS-guided fine needle aspiration needle was easily visualized at depth greater than 4 cm. Flow in gastric, hepatic, and pancreatic parenchymal vessels approximately 1 mm diameter was visualized by using power and color Doppler.
This 10F array US catheter is capable of high-resolution two-dimensional imaging of the gut wall as well as high-quality Doppler imaging. The Doppler capabilities of this equipment may have new GI applications.
超声内镜检查（EUS）需要大量资金投入。使用与标准超声控制台连接的导管进行高分辨率相控阵扫描和多普勒检查，可提高EUS的可及性。最近，一种用于心内检查的电子相控阵超声导管已被研发出来。迄今为止，该技术尚未应用于胃肠道。本研究旨在确定一种新型相控阵扫描超声导管在胃肠道应用的可行性及成像特征。
猪接受全身麻醉。本研究使用一根100 cm、10F、可弯曲导管，其尖端可向大于90度的四个方向偏转。导管尖端装有一个频率可变（5.5 - 10 MHz）、焦距可变的相控矢量阵列换能器。它具备脉冲/彩色和能量多普勒功能。将探头通过治疗性可弯曲乙状结肠镜插入上消化道。通过充满水的避孕套或胃内注水实现声学耦合。使用另一根经口插入的标准EUS引导下细针穿刺针的内镜进行针可视化实验。
易于实现声学耦合。可将胃肠道壁分辨为特征性层次（食管为5层，胃为7层）。在5.5 MHz时，距换能器大于10 cm处的组织分辨率和多普勒成像效果极佳。在深度大于4 cm处可轻松看到22号EUS引导下细针穿刺针。使用能量和彩色多普勒可观察到胃、肝和胰腺实质内直径约1 mm的血管中的血流。
这种10F阵列超声导管能够对肠壁进行高分辨率二维成像以及高质量多普勒成像。该设备的多普勒功能可能在胃肠道有新的应用。
