Which of the following transducers fires the elements in groups?

• A. Linear sequenced array
• B. Phased array
• C. Continuous-wave transducer
• D. Single-element transducer

Answer: (A)

The linear sequenced array transducer operates by activating its elements in groups or sequences rather than firing all elements simultaneously. This method of grouping allows for the generation of images with higher resolution and improved spatial characteristics. The sequential firing of elements creates a "sweep" across the area being examined, enabling better coverage and detail in the resulting image.

In contrast, a phased array transducer uses the principle of variable time delays between firing elements, allowing for electronic steering and focusing without moving the transducer. Continuous-wave transducers operate continuously without the use of pulsed signals, typically used in Doppler ultrasound rather than for imaging. A single-element transducer utilizes only one element for sending and receiving signals, which does not allow for the simultaneous use of groups of elements. Therefore, the linear sequenced array is uniquely designed for firing elements in groups, making it the correct choice in this context.