Answer #36

The correct answer is B. Phase delay is a technique where by changing in timing of the electrical signal to each crystal in the transducer can make the ultrasound beam change direction and sweep from side to side or change the focus [insert transducer phase delay figure]. It was a big technological advance achieved with small crystals that removed the need for moving parts in a transducer. The sweeping from side to side is what creates a 2D echo image. Now one limitation is that the focus can only be made lower than the natural focus but not deeper than the natural focus on the probe. Given all this information only B is is not true and therefore the correct response. All of the other answers are true.