Which description best explains how a triangular image format is produced by ultrasound beam steering?

Which description best explains how a triangular image format is produced by ultrasound beam steering?

• A. Mechanical steering
• B. Electronic steering with small groups
• C. Electronic steering with most elements fired for each pulse-echo sequence. Small time differences steer the beam.
• D. Curved lens

Answer: (C)

Electronic steering uses delays across the transducer elements to bend the emitted wavefront and steer the beam to different angles. When you fire most of the elements for each pulse-echo sequence and apply small time differences across the array, you can sweep the beam across a wide range of angles, creating a fan-shaped, sector-like field. As these steered beams are sampled into scan lines, the display forms a triangular (wedge) image shape because all lines originate from a common source and spread outward with depth. This approach—steering the beam electronically with nearly the full aperture and precise inter-element delays—produces the triangular format most effectively.

Electronic steering uses delays across the transducer elements to bend the emitted wavefront and steer the beam to different angles. When you fire most of the elements for each pulse-echo sequence and apply small time differences across the array, you can sweep the beam across a wide range of angles, creating a fan-shaped, sector-like field. As these steered beams are sampled into scan lines, the display forms a triangular (wedge) image shape because all lines originate from a common source and spread outward with depth. This approach—steering the beam electronically with nearly the full aperture and precise inter-element delays—produces the triangular format most effectively.