Cleveland Family Study

10.11 Pulse Wave (PW) Doppler

10.11.1 Initial Doppler Settings

• “High-Q” function (real-time Doppler analysis) – ON (ATL HDI 3000/5000 CV)

• Advanced measurements – ON (ATL HDI 3000/5000 CV)

• TAM (time averaged mean velocity) – ON (ATL HDI 3000/5000 CV) or mean velocity from the VTI

• Display priority – spectral trace

• Duplex update – 1 sweep

• Sweep speed – To display 3-5 complete waveforms/sweep

• Doppler frequency – As low as possible

• Power – 30-50%

• Receive Gain – Adjust as necessary for optimum signal

• Pulse repetition frequency – 2-4 kHz for baseline

• Baseline – Adjust to display the entire triphasic waveform

• Sample volume length (SVL) – This volume will include the full-lumen width. If a small sample volume is centrally located in the lumen, it will accurately record only the maximum velocities. If this data is then used to calculate flow, the flow will be overestimated since the slower velocities found along the arterial walls will not be included.

• -20º Doppler beam steering with a –70º angle correction. The long footprint of the linear array scanhead, which will be advantageous for recording stable 2-D images, requires Doppler beam steering to acquire an adequate Doppler signal. Since the linear scanhead will be head at a 90º angle of insonation for optimal 2-D intimal definition, it will be necessary to electronically steer the Doppler beam –20º and use a –70º angle correction. Due to the time sensitive nature of the immediate release Doppler and then the 1 minute post release 2-D image, it will be recommended that one not attempt to capture the immediate release Doppler with the one scanhead angle and then try to switch to a 90º scanhead angle to capture the more important one minute post release 2-D image.

10.11.2 PW Doppler Acquisiton

1. While in zoom, a sample volume (SV) will be placed in the lumen and adjusted so that the SV length includes the entire diameter of the lumen.
2. The zoom function will be turned off to make certain the footprint of the linear scanhead is still parallel with the length of the artery, by checking that the proximal and distal diameters are equal.
3. The 1cm zoom box will be turned on without engaging the zoom and the spectral Doppler trace will be activated. This unzoomed duplex view will simultaneously show proper scanhead location and angle, location of the 1cm zoom box along the artery, size, angle, and location of SV along the artery, its position within the zoom box and the quality of the PW spectral signal.
4. Once everything is properly adjusted, the zoom function will be engaged and PW Doppler acquisition will be continued until there is one, high quality sweep, free of any arrhythmia.