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an IVUS thread

Posted: Tue Apr 26, 2011 4:27 pm
by Cece
DrCumming wrote:a seperate ivus thread would be nice....

here is a single image to show a good example.

yellow and purple are the normal vein.

cyan shows the maximal opening diameter of the valves.

Image

Posted: Wed Apr 27, 2011 5:16 am
by 1eye
I suppose this is for the initiates. As a lay-ivus-person looking at a static image I am grateful for the coloured arrows, but it look like an anonymous ellipsoid. I get the two yellow and purple arrows, and can easily believe that is a normal vein, though I have heard they are floppy so I would not be surprised in real life if it moved. I am less sure about the third measurement. I would have to take somebody's word that there is a valve there. I see a white curving line coming up from the bottom of the vessel. Am I warm, cold?

Posted: Wed Apr 27, 2011 6:45 am
by Cece
Yes, the white curving line. It reminds me of the outline of an iris. (The little black circle, slightly pupil-like, in the center can be ignored, it's the guide line itself, iirc. Not part of the vein at all.) Those white fixed curving lines are the edges of the valve.

In the movie it might move some but when the doctors talk about it being at its maximal opening, that ought to be a lot bigger of an opening than it is. It is not because the valve is thickened or malformed.

There! You are an initiate. :)

My question is how do you take the measurements (14.1 and 10.6) and determine a balloon size? Is there agreement among our two doctors on what balloon size would be acceptable for this vein?

Posted: Wed Apr 27, 2011 7:07 am
by 1eye
Must be a bit like looking at the world from a camera mounted on the end of a guitar neck. Too Wayne's World. Ok. What does iirc stand for (I know I'll feel dumb)?

And I never got an answer: any use for Doppler here?

Posted: Wed Apr 27, 2011 8:01 pm
by drsclafani
Cece wrote:Yes, the white curving line. It reminds me of the outline of an iris. (The little black circle, slightly pupil-like, in the center can be ignored, it's the guide line itself, iirc. Not part of the vein at all.) Those white fixed curving lines are the edges of the valve.

In the movie it might move some but when the doctors talk about it being at its maximal opening, that ought to be a lot bigger of an opening than it is. It is not because the valve is thickened or malformed.

There! You are an initiate. :)

My question is how do you take the measurements (14.1 and 10.6) and determine a balloon size? Is there agreement among our two doctors on what balloon size would be acceptable for this vein?
good question cece

IVUs also gives you cross sectional area which makes more sense that the max/min diameters since ballooning will reshape the vein into the shape of the balloon. I have calculated cross sectional areas for each balloon and try to dilate with a balloon that will have about 50% greater CSA than the vein during IVUS, erring on side of less rather than more. If repeat IVUS shows persistent valvular stenosis, i will increase size of balloon by 2 mm.

Generally this tends to disrupt the valvular "fusion" quite nicely. Still no thromboses with this modification.

Posted: Thu Apr 28, 2011 8:51 pm
by Cece
drsclafani wrote:IVUs also gives you cross sectional area which makes more sense that the max/min diameters since ballooning will reshape the vein into the shape of the balloon.
That makes plenty of sense.
I have calculated cross sectional areas for each balloon and try to dilate with a balloon that will have about 50% greater CSA than the vein during IVUS, erring on side of less rather than more. If repeat IVUS shows persistent valvular stenosis, i will increase size of balloon by 2 mm.
So you are oversizing, but in a precise way? Or is this within normal parameters for venoplasty?
Generally this tends to disrupt the valvular "fusion" quite nicely. Still no thromboses with this modification.
It's very good news about the lack of thromboses. If those tend to happen either within the first days or within the first month, then I'd expect you to have seen some by now.

Posted: Sat Apr 30, 2011 3:31 pm
by DrCumming
1eye wrote:I suppose this is for the initiates. As a lay-ivus-person looking at a static image I am grateful for the coloured arrows, but it look like an anonymous ellipsoid. I get the two yellow and purple arrows, and can easily believe that is a normal vein, though I have heard they are floppy so I would not be surprised in real life if it moved. I am less sure about the third measurement. I would have to take somebody's word that there is a valve there. I see a white curving line coming up from the bottom of the vessel. Am I warm, cold?
The valves are often very difficult to see. And even harder to capture a single image of. The software we have to make real time movies of the IVUS is not working well right now and its low priority item for my IT guys...

But yes, its the vague curved lines near the "3" mark.

Posted: Sun May 01, 2011 12:26 am
by drsclafani
DrCumming wrote:
1eye wrote:I suppose this is for the initiates. As a lay-ivus-person looking at a static image I am grateful for the coloured arrows, but it look like an anonymous ellipsoid. I get the two yellow and purple arrows, and can easily believe that is a normal vein, though I have heard they are floppy so I would not be surprised in real life if it moved. I am less sure about the third measurement. I would have to take somebody's word that there is a valve there. I see a white curving line coming up from the bottom of the vessel. Am I warm, cold?
The valves are often very difficult to see. And even harder to capture a single image of. The software we have to make real time movies of the IVUS is not working well right now and its low priority item for my IT guys...

But yes, its the vague curved lines near the "3" mark.

mike
would you agree that the brightly echogenic material represents a thickened valve? I am using that as a criteria for abnormality. , pluse the inability of the valve to completely open and close. There is also the double echo sign on the longitudinal images to look at.