Two-dimensional (2D) transthoracic echocardiography is one of the most used diagnostic tools in clinical cardiology. Similarly, 2D transesophageal echocardiography is considered an indispensable tool for cardiologists and cardiac anesthesiologists worldwide. However, because of their tomographic nature, both techniques display only thin cut planes of a given area of the heart, which are far from representing the “anatomic reality.” It is widely accepted that experienced echocardiographers are able to reconstruct mentally a three-dimensional image of any cardiac structure on the basis of their interpretation of multiple tomographic slices. However, this may not be the case with less experienced echocardiographers. In particular, the authors noticed that less experienced echocardiographers are almost totally unaware of which structures lie “nearby” a given 2D tomographic plane, that is, what is adjacent in the elevation plane. In this article, the authors report the use of three-dimensional transesophageal echocardiographic images to discover which structures are located nearby (i.e., “behind” and “in front”) the corresponding 2D cross-sections. The authors believe that this novel use of three-dimensional echocardiography is a unique aid to disclose what cannot be seen in a given 2D cross-section, thereby expanding our understanding of 2D echocardiographic anatomy. This may be an effective method to encourage all to “think” in three dimensions, even when they use 2D echocardiography.

二维（2D）经胸超声心动图检查是临床心脏病学中最常用的诊断工具之一。同样，二维经食道超声心动图被认为是全世界心脏病专家和心脏麻醉专家必不可少的工具。但是，由于它们的层析成像性质，这两种技术仅显示心脏给定区域的细切平面，这远不能代表“解剖学现实”。经验丰富的超声心动图医师能够根据他们对多个断层扫描切片的解释，在心理上重建任何心脏结构的三维图像，这已被广泛接受。但是，经验不足的超声心动图检查员可能并非如此。尤其是，作者注意到，经验不足的超声心动图检查人员几乎完全不知道哪个结构位于给定的二维断层扫描平面“附近”，即在仰角平面附近。在本文中，作者报告了使用三维经食道超声心动图图像来发现哪些结构位于相应2D横截面的附近（即“后面”和“前面”）。作者认为，三维超声心动图的这种新颖使用是揭示在给定2D横截面中看不到的东西的独特帮助，从而扩展了我们对2D超声心动图解剖学的理解。这可能是鼓励所有人从三个维度“思考”的有效方法，即使他们使用2D超声心动图也是如此。在本文中，作者报告了使用三维经食道超声心动图图像来发现哪些结构位于相应2D横截面的附近（即“后面”和“前面”）。作者认为，三维超声心动图的这种新颖使用是揭示在给定2D横截面中看不到的东西的独特帮助，从而扩展了我们对2D超声心动图解剖学的理解。这可能是鼓励所有人从三个维度“思考”的有效方法，即使他们使用2D超声心动图也是如此。在本文中，作者报告了使用三维经食道超声心动图图像来发现哪些结构位于相应2D横截面的附近（即“后面”和“前面”）。作者认为，三维超声心动图的这种新颖使用是揭示在给定2D横截面中看不到的东西的独特帮助，从而扩展了我们对2D超声心动图解剖学的理解。这可能是鼓励所有人从三个维度“思考”的有效方法，即使他们使用2D超声心动图也是如此。作者认为，三维超声心动图的这种新颖使用是揭示在给定2D横截面中看不到的东西的独特帮助，从而扩展了我们对2D超声心动图解剖学的理解。这可能是鼓励所有人从三个维度“思考”的有效方法，即使他们使用2D超声心动图也是如此。作者认为，三维超声心动图的这种新颖使用是揭示在给定2D横截面中看不到的东西的独特帮助，从而扩展了我们对2D超声心动图解剖学的理解。这可能是鼓励所有人从三个维度“思考”的有效方法，即使他们使用2D超声心动图也是如此。