What is an advantage of transducer arrays?

• A. Transducer arrays produce pure, single-frequency beams
• B. Transducer arrays enable mechanical steering
• C. Transducer arrays enable electronic focusing and steering
• D. Transducer arrays have greater dynamic range, resulting in more displayed shades of gray

Answer: (C)

Arrays let you shape the ultrasound beam electronically by controlling the timing of each element’s pulse. By applying precise time delays across the elements, the emitted waves add up constructively at a chosen focal point, providing focused energy and better lateral resolution at that depth. Varying those delays across the array also tilts the beam, steering it to look in different directions without moving the probe, enabling real-time scanning. This combination of electronic focusing and steering is the main advantage of transducer arrays.

The other ideas aren’t unique advantages of arrays. Producing a pure, single-frequency beam isn’t what arrays guarantee, since pulses are short and broadband. Mechanical steering requires moving the transducer, whereas arrays accomplish steering electronically. Dynamic range is more about the receiver electronics and processing, not the array’s ability to focus or steer.