Which type of ultrasound wave propagates parallel to the direction of travel?

Which type of ultrasound wave propagates parallel to the direction of travel?

• A. Longitudinal waves
• B. Transverse waves
• C. Surface waves
• D. Circular waves

Answer: (A)

Longitudinal waves are the type where particle motion is parallel to the direction the wave travels. In ultrasound, the transducer creates compressions and rarefactions in the tissue, causing the medium to oscillate along the same line as the beam’s travel. That compressional, or longitudinal, motion allows the wave to propagate through both fluids and solids in the body. Transverse waves have particle motion perpendicular to the direction of travel, which isn’t how ultrasound primarily propagates in soft tissues. Surface waves travel along interfaces with motion confined near the surface, and circular waves aren’t the standard mode for core ultrasound propagation.

Longitudinal waves are the type where particle motion is parallel to the direction the wave travels. In ultrasound, the transducer creates compressions and rarefactions in the tissue, causing the medium to oscillate along the same line as the beam’s travel. That compressional, or longitudinal, motion allows the wave to propagate through both fluids and solids in the body.

Transverse waves have particle motion perpendicular to the direction of travel, which isn’t how ultrasound primarily propagates in soft tissues. Surface waves travel along interfaces with motion confined near the surface, and circular waves aren’t the standard mode for core ultrasound propagation.