The descriptor for a Doppler shift where the received frequency is less than the transmitted frequency is:

The descriptor for a Doppler shift where the received frequency is less than the transmitted frequency is:

• A. Positive
• B. Negative
• C. Zero
• D. Inverse

Answer: (B)

When the received frequency is lower than the transmitted frequency, the Doppler shift is negative. This negative shift indicates that the moving target (such as blood) is traveling away from the transducer along the ultrasound beam. If the target were moving toward the transducer, the shift would be positive (f_r would be greater than f_t). A zero shift occurs when the motion is perpendicular to the beam or there’s no motion. So the descriptor for a lower received frequency is Negative.

When the received frequency is lower than the transmitted frequency, the Doppler shift is negative. This negative shift indicates that the moving target (such as blood) is traveling away from the transducer along the ultrasound beam. If the target were moving toward the transducer, the shift would be positive (f_r would be greater than f_t). A zero shift occurs when the motion is perpendicular to the beam or there’s no motion. So the descriptor for a lower received frequency is Negative.