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In relation to continuous-wave Doppler imaging: a. It uses a transducer with two slightly angled crystals b. A good range resolution can be achieved c. High velocities can be measured accurately d. It cannot be used in pregnancy due to the high energy deposited by the continuous ultrasound wave e. A continuous Doppler signal is usually presented to the user as an audible sound |
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Answer» a. True. It uses two separate crystals with overlapping beams, which act as a receiver and a transmitter. b. False. There is no depth discrimination. c. True. This is the main advantage of the continuous-wave Doppler. d. False. Monitoring the fetal heartbeat is one of its main applications. e. True. A continuous-wave Doppler is mainly used in simple handheld systems that present the signal this way. The original frequency is removed from the received frequency leaving the Doppler shift (‘beat’) in the audible range. The pitch of the sound is proportional to the velocity of the object. |
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