ARDMS (American Registry for Diagnostic Medical Sonography) Practice Test

If a carotid duplex exam is performed on a patient with a 7MHz transducer and a 14 MHz transducer, which transducer will display a shift that is greater?

1. The 14 MHz transducer

2. The Doppler shift is the same with both transducers.

3. The 7 MHz transducer

4. The Doppler shift cannot be identified with this information.

The correct answer is: The 14 MHz transducer

The correct answer is A. The 14 MHz transducer will display a shift that is greater than the 7 MHz transducer. This is because Doppler shift is directly proportional to the frequency of the transducer used. Higher frequency transducers produce a greater Doppler shift, as they are more sensitive to detecting higher-frequency signals. Therefore, in this scenario, the 14 MHz transducer will display a greater shift compared to the 7 MHz transducer. Option B is incorrect because the Doppler shift is not the same with both transducers due to their different frequencies. Option C is incorrect as the 7 MHz transducer will display a smaller shift compared to the 14 MHz transducer. Option D is incorrect as the Doppler shift can be identified based on the information provided about the transducer frequencies.