In diagnostic ultrasonography sound pulses travel through media. ______ arising from structures in the body return to the transducer and are processed into ______.

• A. Echoes; Images
• B. Reflections; Images
• C. Refractions; Diagrams
• D. Reflections; Diagrams

Answer: (B)

When a diagnostic ultrasound probe sends a sound pulse into the body, it travels through tissues until it meets interfaces with different acoustic properties. At these boundaries, part of the sound energy is reflected back toward the transducer. Those returning signals are reflections of the original pulse (often called echoes), and the ultrasound system uses their timing and strength to construct a visual image. So, reflections arising from tissue interfaces return to the transducer and are processed into images on the screen. The other terms don’t fit because refractions are bending of waves within tissues and don’t by themselves produce the image, while diagrams isn’t how ultrasound displays tissue structures.