Dear Steve,
Thank you so much for your detailed response. Carotid is really challenging when it is not a straightforward NAD scan.
1) I do think that beam steering is overused, especially with machines like the Philips Affiniti 70 where people rave about how wide of a range the beam steering has. What I have always learnt from angle correcting Portal vein, MCA, UA, etc. is that you always try to get Doppler angle to 0 deg, not as close to 60 deg, so I am very confused when people say to keep it 60 deg for Carotid.
Also, I did not know there are ways to reduce plaque size like Statins.
2) I have not used Triplex but now I know why not to use them. Do you use I-scan (or Q-scan?) (on Canon machines) to let the machine optimise your Pulse wave reading? I often have to adjust the scale manually to have a nice spectral trace graph.
3) More questions on colour: apart from colour scale, do you ever adjust colour frequency to increase sensitivity to light up the vessel? Or do you use Power Doppler to delineate the subtle hypoechoic plaques?
4) If I ‘walk the vessel’ as I obtain the trace in tortuous part of the vessel, then by what you say, I should stop and change the beam steering after the bend then.
5) I did another scan where the patient is young and heathy, but her CCA prox and dist on both sides are high (150 at prox to 130 cm/s at dist). There is no obvious plaques at all. I obviously can’t call there is a 50% stenosis in CCA but how do you explain the high velocities in the CCA?
6) Sometimes I cannot identify the vertebral art between the transverse processes at mid neck. But as I use Colour and sweep laterally and medially, I can see a vessel diving down and the waveform is like vert art. Is this a normal variation that vert art is outside the vertebrae?
Best regards,
Linh