For a large patient, which transducer would provide the least amount of signal attenuation?

For a large patient, which transducer would provide the least amount of signal attenuation?

• A. 3.5 MHz
• B. 5.0 MHz
• C. 7.5 MHz
• D. 2.5 MHz

Answer: (D)

When ultrasound travels through tissue, higher frequency waves lose energy more quickly than lower frequency waves. This means attenuation—the weakening of the signal—rises with frequency. For a large patient, getting the signal deep into the body is more important than having the sharpest possible image, so you choose the transducer with the lowest frequency. That transducer will experience the least attenuation as it penetrates to deeper structures. The trade-off is that lower-frequency transducers offer lower spatial resolution, but they maximize penetration for bigger patients.

When ultrasound travels through tissue, higher frequency waves lose energy more quickly than lower frequency waves. This means attenuation—the weakening of the signal—rises with frequency. For a large patient, getting the signal deep into the body is more important than having the sharpest possible image, so you choose the transducer with the lowest frequency. That transducer will experience the least attenuation as it penetrates to deeper structures. The trade-off is that lower-frequency transducers offer lower spatial resolution, but they maximize penetration for bigger patients.