The geometrical relationship between the human esophagus and left ventricle: implications for three-dimensional ultrasonic scanning.

To establish design parameters for a transesophageal ultrasonic probe to image the left ventricle (LV) in three dimensions, the geometrical relationship between the esophagus and the heart was studied in computed tomographic sections of ten humans. Points describing the esophageal centerpoint and the left-ventricular endocardium were digitized. Algorithms were developed to determine from any esophageal viewpoint the ranges of motion required to cover the LV with four modes of scanning; transverse oblique, longitudinal oblique, rotary and linear.