Biplane transesophageal echocardiography: technique, image orientation, and preliminary experience in 131 patients. Transesophageal echocardiography with use of a uniplane phased-array transducer with a transverse or horizontal scanning plane has become a well-established tool for evaluating cardiovascular diseases. Recent introduction of biplane probes has enhanced the diagnostic capability of this imaging technique. This article discusses the technique of biplane transesophageal echocardiographic examination and image orientation. The diagnostic value and advantages of various biplane transesophageal images of the heart, aorta, and aortic arch from various esophageal positions are described. 