In 1918, Bordet and Vaquez1 described two methods for measuring enlargement of the left ventricle in the anteroposterior plane or depth. Measurements on the orthodiagraphic tracing or teleoroentgenogram of the heart have been developed to the point where they are essential to careful cardiac study. But they give information concerning only the measurements of the heart in the transverse plane. It can be appreciated how valuable would be additional information concerning enlargement of the left ventricle in the anteroposterior plane. In view of this fact, and because these methods are gaining attention and prominence in the roentgen-ray laboratories abroad, a critical study of the value of these methods was made in a series of seventy subjects and nine anatomic cross sections.
Imagine the patient standing, facing the fluoroscopic screen, as the cross section Figure 1 represents, with the target situated 60 cm. from the screen. The diaphragm is shut