1. German/Doepp/Doppler Study:
In the current issue of the Annals, Florian Doepp, M.D., and colleagues in Germany performed an extended extra- and trans-cranial color-coded sonography study on 56 MS patients (36 female; 20 male) and 20 control subjects (12 female; 8 male). The analysis included extra-cranial venous blood volume flow (BVF), internal jugular vein (IJV) flow analysis during Valsalva maneuver (VM), as well as tests included in the CCSVI criteria.
As I've said before, the problem with the Doepp study was position of the doppler wand. It assessed jugular vein narrowing in the “sagittal” plane (the ultrasound probe is placed parallel to the length of the vessel). The Zamboni technique uses the “transverse” plane ( the probe is placed at a 90 degree angle to the length of the vessel) to look for narrowing, webs, or abnormal valves that Dr. Zamboni believes are often missed in the sagittal plane examination.
If the wand is used in the sagittal manner--it picks up collateral flow...that's how the doppler technician at Stanford gave Jeff a "normal" result, but MRV showed it was a tortuous collateral, not the jugular vein (which was 95% gone) taking the blood back.
What has to be appreciated here is that imaging of veins using doppler ultrasound is by no means easy - and that goes for Zamboni too. This is not for want of trying over the years, the holy grail of venous doppler ultrasound is the detection of DVTs in the lower limbs, but despite the relative ease of accurately imaging the deep leg veins compared to those in the neck and head, and continuing advances in imaging technology, doppler is still nowhere near to supplanting venography for this.
As far as the study goes, they're not using a "doppler wand" which would be completely useless for this, they're using colour flow doppler imaging superimposed on a conventional grey-scale ultrasound image. The doppler part of this doesn't work so well when imaging in a transverse plane across any blood vessel, as there is effectively no doppler signal in this orientation unless you tilt the ultrasound probe anteriorly or posteriorly, in which case you no longer have a true transverse section of the blood vessel. You will see something, but unless you tilt the probe at a decent angle it'll be very small doppler shifts and very noisy, so if e.g. 2 blood vessels are not exactly parallel you could think that in one of them the blood is going the wrong way when it's really just the geometry of the localised anatomy. There is no good reason I can think of to suppose that a transverse image will be more liable to accurately identify the jugular than a sagitall image with superimposed doppler flow information, I would actually have thought quite the opposite. A good sonographer would use both anyway, although in general the sagitall is much better for seeing the bloodflow, and the transverse while useful when scanning arteries is more often used only for orientation when looking at veins.
Now onto the jugular, this is a very difficult vein to image. First of all every patient is different, sometimes you get beautifully clear images and you see clean doppler flow information superimposed where the blood vessels are, other times it's just impossible to see anything and your doppler information is a noisy mess. With some patients it might not even be possible to accurately image and measure the adjacent carotid artery, and this is far far easier than doing it for the jugular. The other thing about the jugular is that often it is continually collapsing and opening up again as you image it. This depends on factors like - whether the patient is sitting up or lying down, the angle of the bed, is their head turned to the side or tilted back, their breathing, maybe even the pulsation of the adjacent carotid artery. The point about the position of the head is important - to get a decent image and see the bloodflow you often have to turn the head to one side and/or tilt it back - there is no standard position for doing this test, you have to be pragmatic. Pressure from the probe is also a problem, especially with transverse images. You need to get a good contact between the probe and the skin to get a good image, and for some patients depending on the shape of their neck this means you've got to press down a bit to get the image. Press too hard and the jugular compresses, press too lightly and you can't see it properly. So you're trying to measure the blood flow and look for narrowings in a blood vessel which in many cases is continually opening and closing anyway, and you've manipulated your patient into a position where you can get good image quality and/or where the jugular opens up and you can get a good view of it - not easy and not at all objective.
It gets even worse with the other extracranial veins which are far more difficult to image, and if you want to try and look at the intracranial veins with doppler ultrasound you'll be doing a lot of squinting at that fuzzy grey screen.
It would be great if CCSVI turned out to be something important in MS, but I'm not surprised that the ultrasound studies are showing completely different things. This is not an exact science, and even for far easier and more routine investigations than this the results will vary greatly depending on the skill of the sonographer. Also people will often see what they want to see when they've convinced themselves of the validity of their own ideas. I'm sure that the pharma companies want to cure people AND make money at the same time, but I'm equally sure that medics and scientists want to cure people AND get published at the same time.