What I've learned about vascular ultrasonography: measurement is highly sonographer-dependent and interpretation is highly radiologist-dependent. Within the same practice, people may use different terminology and even standards. Do not expect a lot of precision.
Anyway, the results:
- Carotids clear. Not imaged previously so no idea if any change, but this time: at most minimal plaque, no significant stenosis. Cool!
- Abdominal aorta: Unchanged; no signs of aneurysm.
- External iliacs: Not reported previously. This time: "Plaque was noted". How much? Who knows? I assume that without any further notes it's not significant.
- Right leg: Not imaged previously, but obviously affected. This time: Stenosis of "at least 50%" in the SFA above the knee, with a peak systolic velocity of 319 cm/second and a ratio of ~2.5 for bad segment vs proximal segment. No surprise there. "Dampened monophasic flow" in the 3 arteries below the knee. Ditto.
- Left leg: The big one, and the most annoyingly ambiguous part of this study, particularly for the superficial femoral artery.
Previously there was a "5cm occlusion 13 cm above the knee" in the SFA. This time: "The occlusion demonstrated previously was not visualised". Has it gone away? Did the previous guys see something that wasn't there? Did the guys this time miss it? My doc thinks it very unlikely that it actually went away, and I suppose I have to agree, I guess ... But actually I don't really understand how there could be that much uncertainty over a 5cm occlusion - it's not a tiny little thing?
Further, this time "there was extensive plaque in the SFA" but no stenosis estimate given. And no velocity measurements apart from, "No major velocity increase detected in the SFA". Compared to what? Last time? Bad segment versus adjacent segment?
Previously, one major collateral vessel bypassing the SFA occlusion was noted. This time, "collateral vessels were seen in the distal thigh". A couple, a bunch? I guess this is really the main clear positive change from this study: more collaterals = better flow and no doubt a big part of why I can walk a lot better. Conversely, promoting their development is a main rationale for walking therapy. But it would be nice to have a bit more precision.
For the left profunda femoral artery: Last time it was "50% - 75% estimated stenosis" vs this time "peak systolic flow of 214 cm/sec consistent with a stenosis" but there was no velocity measurement for an adjacent segment and no stenosis estimate. So what's the comparison? No particular difference? I think > 200 cm/sec is generally a diagnostic for 50%+ stenosis, but I thought that needed to be combined with a 2+ ratio between adjacent segments? Would be nice to have some more consistency.
Finally, "Dampened monophasic flow in all 3 below-knee arteries". Last time: "Scant, monophsaic flow through all 3 vessels". Is there any difference between "dampened" and "scant"?
Anyway, bottom line is that there is significant PAD in both legs, no surprise, but maybe some hopeful signs of improvement, certainly in collateral formation, and every reason to keep on doing what I'm doing. I'll get another study done in 6 months or so.