Dynamic receive focusing uses which of the following?

• A. Mechanical means to focus the beam
• B. Time delays to excite array elements
• C. Time delays before echo signals from array elements are combined
• D. All of the above

Answer: (C)

Dynamic receive focusing relies on adjusting the timing of the signals after they’re received. The system applies time delays to the echoes from each element so they align in time when they’re summed. By changing these delays with depth, the receiver can focus at different points along the scan line without changing the transmitted beam. This is distinct from mechanical focusing or from delaying the transmit excitations; those would affect the beam during transmission, not during reception. So, the description that best fits dynamic receive focusing is applying time delays to the received echoes before they are combined.