Physics - Doppler Instrumentation and Hemodynamics Exam

Physics - Doppler Instrumentation and Hemodynamics Exam C. Gain What Doppler control should be adjusted to optimize this Doppler spectral waveform? A. Wall filter B. Packet size C. Gain D. Pulse repetition frequency E. Baseline C. Frequency shift is increased Which of the following best describes the Doppler frequency shift when you encounter high velocities within a vessel? A. Amplitude is increased B. Power is increased C. Frequency shift is increased D. Bandwidth is decreased E. All of the above E. All of the above Which of the following could be a source of color Doppler signal? A. Blood flow B. Breathing motion C. Cardiac motion D. Transducer motion E. All of the above E. All of the above The Reynold's number increases with increasing: A. Flow speed B. Vessel diameter C. Blood density D. Blood flow viscosity E. All of the above B. Bruit What is the source of the bright echoes indicated by the arrow in this Doppler waveform? A. Spectral broadening B. Bruit C. Aliasing D. Mirror imaging E. Range ambiguity B. Packet size The terms ensemble length and dwell time are synonymous with: A. Persistance B. Packet size C. Pulse repetition frequency D. Color threshold E. Autocorrelation A. Doppler angle of interrogation near 90 degrees During Doppler interrogation of the carotid artery, you detect spectral mirroring. Which of the following is a common cause of this artifact? A. Doppler angle of interrogation near 90 degrees B. Doppler angle of interrogation near 0 degrees C. Wall filter set too high D. PRF set too low E. Doppler gain set too low B. Media The layer of the vessel wall that contains smooth muscle fibers is: A. Adventitia B. Media C. Intima D. Internal elastic lamina E. External elastic lamina C. Will be higher than The Frank-Starling mechanism helps to explain that when an arrhythmia is present, the peak systolic velocity following a heart cycle with a longer time interval ____ one with a shorter time interval. A. Will be equal to B. Will be lower than C. Will be higher than D. Will be unrelated to E. Will be unpredictable, and lower than D. The Nyquist limit is decreased Which of the following occurs when you lower the pulse repetition frequency? A. The wall filter is increased B. The frame rate is increased C. The line density is increased D. The Nyquist limit is decreased E. The Doppler frequency is decreased E. Lower the wall filter In the following waveform, the end-diastolic flow velocity cannot be measured. What control adjustment should be performed to obtain this measurement? A. Increase the pulse repetition frequency B. Decrease the angle of incidence C. Lower the zero baseline D. Increase the Doppler gain E. Lower the wall filter B. Fourier analysis What method is most commonly used to perform spectral analysis for pulsed Doppler? A. Zero-crossing detection B. Fourier analysis C. Reynolds number