Harada M, Imamura Y, Hasegawa N, Yano K, Suzuki M, Nishizawa S, Hirai H, Machii K
Third Department of Internal Medicine, Toho University School of Medicine, Tokyo.
J Cardiol Suppl. 1991;26:3-11, discussion 12-3.
Transesophageal color Doppler flow imaging has proved to provide an accurate and sensitive information for diagnosis of valvular regurgitation. However, it is necessary to understand the difference in the display of color Doppler image between transesophageal and conventional transthoracic transducers for quantitative assessment of valvular regurgitation. In this study, the effects of the depth between transducer and jet flow on color Doppler flow imaging were evaluated with the transesophageal (3.75 MHz) and conventional (2.5 MHz) transducers by using a flow phantom. A flow circuit was filled with saline in which nylon corpuscles (average diameter; 5 microns) were suspended to enhance the Doppler effects. A turbulent jet with constant flow velocity (Reynolds number; 3500) stimulating valvular regurgitant flow was produced in a water bath through a small orifice (2 mm) by constant driving pressure (100 mmHg). Color jet imaging in the long- and short-axis views were observed at each depth with both transducers. The measurement was made every 1 cm in depth from 3 to 12 cm. The color gain setting was fixed at the optimal point so as to get the maximal flow image with the minimal static background noise. We obtained larger image of the color jet signal with the conventional than the transesophageal transducer. Although a mosaic pattern was displayed more distinctly with the transesophageal transducer compared with that of the conventional transducer, the transesophageal image tended to become indistinct in the depth deeper than 8 cm. On the other hand, the transthoracic image was maintained relatively constant at any depth.(ABSTRACT TRUNCATED AT 250 WORDS)
经食管彩色多普勒血流成像已被证明能为瓣膜反流的诊断提供准确且敏感的信息。然而，为了对瓣膜反流进行定量评估，有必要了解经食管与传统经胸换能器在彩色多普勒图像显示上的差异。在本研究中，通过使用血流模拟装置，利用经食管（3.75兆赫）和传统（2.5兆赫）换能器评估了换能器与射流之间的深度对彩色多普勒血流成像的影响。一个血流回路充满了盐水，其中悬浮着尼龙微粒（平均直径；5微米）以增强多普勒效应。通过在恒压（100毫米汞柱）下通过一个小孔（2毫米）在水浴中产生具有恒定流速（雷诺数；3500）的模拟瓣膜反流的湍流射流。用两个换能器在每个深度观察长轴和短轴视图中的彩色射流成像。从3厘米到12厘米，每隔1厘米进行一次深度测量。彩色增益设置固定在最佳点，以便在最小静态背景噪声下获得最大血流图像。与经食管换能器相比，我们用传统换能器获得了更大的彩色射流信号图像。尽管与传统换能器相比，经食管换能器显示的镶嵌图案更清晰，但在深度超过8厘米时，经食管图像往往会变得模糊。另一方面，经胸图像在任何深度都保持相对恒定。（摘要截断于250字）
