What does the term "pulsed echo" refer to in sonography?

The term "pulsed echo" in sonography specifically refers to the process of sending short bursts of ultrasound waves into the body and measuring the time it takes for the echoes to return after interacting with tissues. This method allows for the determination of the distance to various structures within the body, as the time taken for the echo to return is directly related to the depth of the tissue that reflected the sound.

In this technique, ultrasound transducers emit a pulse of sound and then pause briefly to listen for the echoes that bounce back. This pulsing system is essential for creating images of internal organs and tissues, as it enables the capture of spatial information in a manner that allows for real-time imaging and assessment.

The other methods listed in the question do not align with the definition of pulsed echo. Continuously emitting sound waves, for example, would not allow for precise distance measurement and imaging as it would blend the emitted sounds without the ability to isolate echoes from specific structures. Similarly, receiving echoes constantly or deploying a single continuous sound wave do not employ a pulsed approach, which is crucial for effective imaging in sonography.