Sonography Principles and Instrumentation (SPI) Practice Exam

The term that accurately describes the strength of the signal in ultrasound is amplitude. Amplitude represents the maximum value or strength of the wave, which directly affects the brightness of the echo displayed on the ultrasound image. In ultrasound, a higher amplitude indicates a stronger return signal from the tissue, which can enhance the clarity and detail seen in the final image. This concept is crucial for sonographers as it influences image quality and diagnostic capabilities.

While intensity may also seem relevant, it is a measure of the power per unit area of the ultrasound wave and is related to amplitude, but it does not specifically refer to the strength of the signal in the same direct manner. Frequency, on the other hand, relates to the number of cycles of the wave per second and has no direct correlation with signal strength. Impedance is a property related to how ultrasound waves interact with different tissues, influencing how much of the wave is reflected or transmitted, but it does not define strength itself. Thus, amplitude is the most appropriate term to describe the strength of the ultrasound signal.