Test object for measurement of section thickness at US.

A simple phantom was used to test the ultrasound beam profile in the elevation direction (perpendicular to the scanning plane). Based on the inclined plane method, the phantom allowed direct clear display of the section thickness over the whole exploration depth on a single standard ultrasonographic image. This was demonstrated with one- and one and one-half-dimensional arrays. The results showed the efficiency of electronic focusing in the elevation plane associated with one and one-half-dimensional arrays.