 So, if you go online, you're going to see that there's more cases than I actually have on here. I've actually trimmed it a little bit to try and fit within the time that we have and to get us closer to doing the hands-on where so we have more time to analyze cases in the lab. Is that not showing up? Oh, there we go. Perfect. So, we're going to talk about left atrial appendage cases. And before we start, just a brief review. The left atrial appendage is the most common site for thrombus, okay? And that's why we actually care about it a lot. Atatomically, it's attached to the left anterior portion of the left atrium, and it consists of pectinate muscles. And there are four types of left atrial appendage morphologies that we commonly see. Here's the pictures. These are actually from CT images because those are the best ways to actually look at the left atrial appendage. So the windsock, I think we see a lot, and then there's the cactus appearance over there, the chicken wing and the cauliflower appearance. And so when you're looking at atrial appendage, you want to make sure that you're getting through the entire appendage and you're not missing parts or lobes or sublobes of the appendage. So this is where I think there aren't going to be a lot of pretty 3D pictures on this. What there is going to be in this part of the talk is there's going to be a lot of bi-plane imaging because how you can actually look through the valve and make sure you're not missing anything as you sweep through the valve, or not the valve, as you sweep through the appendage and how you can make sure you capture all the lobes and you see the entire portion of the lobes. Because if you look at the chicken wing, you have a portion that always folds back versus if you're looking at the windsock. The windsock's the easiest one to assess because it's one big pocket. The chicken wing bends back. You've got to make sure you see that, or if you've got the cactus or cauliflower, you've got multiple arms. You've got to make sure that you see all these arms and you're not missing part of it. It's very easy to clear one part of it, but you may not realize that there's another portion that you've not seen, and this is where bi-plane and multi-plane imaging actually helps. So this is a case of a 70-year-old gentleman who presents with permanent atrial fibrillation, which means that we've given up on trying to get him back to normal rhythm. He had a variceal bleed, so he can't have oral anticoagulation, so he's now being worked up for left atrial appendage closure by device. So one of the things we have to do before we go for the device is we have to make sure that there is no clot in the left atrial appendage, and then we also have to assess for the size. Now, there's a couple of nice papers showing that you should try and make sure these people are a little bit fluid-loaded, so that way you get the appendage a little bit larger than you would normally see in someone who's dry, because you want to make sure you get the most accurate sizing for the device. So there's a couple of ways that we measure the appendage in the cath lab. We do 2D planar measurements in two different views, and we actually measure right at the orifice as well as a centimeter in to where the landing zone will be. We do it both on 2D imaging, and then we also get a 3D dataset, and we do the same thing on 3D. And in 3D, a lot of the times you realize when you go in and you align your plane, so there's the 3D volume, and we've got two different perpendicular planes where we're lined up at the orifice, and you can see that it's a nice oval orifice, and that's how we can get a nice measurement for the cath lab there. And so this is what we do for 3D. And then the other way you can actually assess the left atrial appendage, sometimes if you have a very nice clean picture, is that you can take the eye slice, which I think a net showed an example for the mitral valve, but you can do it for the left atrial appendage too. And when you take your 3D dataset and you put your slices all the way down, going sort of parallel to the orifice, and you can then get slices going all the way down into your left atrial appendage, and you can actually get a true nice measurement from there. The other thing is you can rotate it so that you're going parallel to the length of the appendage, and then you can actually look through the entire appendage for any cloths or anything else like that. So those are kind of two different ways you could approach using eye slice to take a look at the left atrial appendage. And so this is one of the few 3D, true 3D volume rendered images I have showing that we actually put a device in, and you see the nice figure 8 shape of that occluder in the left atrial appendage after the device is closed. But going back to the most common question that we have is clot or no clot. So in this case, this is just mostly to show you that we see this a lot. Sometimes you get this haziness that you can't clear, and then what you want to do is you want to make sure that you can actually see the little tips of the appendage here. And so sometimes what we do, and a lot of the times, is we'll take our multi-plane mode, the X-plane mode, and we'll actually sweep through, and we'll go through what we think is the tip and what we don't think is the tip. And as you see here, this line is your plane, and then on your bi-plane image, what you have to realize is this is straight down the middle of that. So the middle is where your line is, and then everything else is on either side of that. And when you look at it, you can actually see there's a little tip here. So we're not seeing the full in this plane. You realize that there is another little portion of the appendage that you don't actually really appreciate in this plane. This is where there's the value. Some people believe in doing sweeps, they sweep through, but this is a way of sweeping where you hold your image and then you just use the bi-plane to sweep through your image. Okay. We do do this measurement where we Doppler in to look at velocities. I'm not sure anyone's ever made a clinical decision based on the Dopplers, but we find it reassuring if it's greater than 40, if it's less than that, then we kind of have a higher suspicion there. And then some people believe in doing the M mode, and that's what I have in there. Contrast, I know this is outside the 3D. If we have a suspicion and we can't clear it, we do contrast. What you want to do though is you want to bring your mechanical index down. The second thing is you want to look at your left atrial appendage as the contrast comes swirling in. If you have a small thrombus, if the left atrial appendage gets filled, it's going to surround the thrombus so you're not going to see it. So you want to look as it comes swirling in. And then the second thing is you want to switch into different views, okay, as you want to do that. So this patient, I'm just going to say, had no thrombus, and after all of that, we cleared it from there. So if you can't see anything, then you use your different techniques to try and visualize it and make sure that you're not missing a thrombus there. So here, does anyone, so this is real life imaging. And so here you see there's a nice long shadow going here, making it tough to see the appendage. We switch to another view to actually see, and then we see something flickering over here. Do you see that? I've heard it for a while. Is that real? Is that not real? What are we going to say? It's a very unusual place. It's near the opening of the valve. Does everyone see what I'm looking at? If you don't, raise your hands. Okay. Okay. So we thought we saw something there. So what we do is we biplane. So we use biplane to confirm what we're seeing. It gives you another plane. Sometimes we rotate into that plane to see it. And this is actually called. There's a little bit of a mobile density. It's independently mobile. It's moving separately from everything else. It's not a traditional place, but we actually called that as thrombus. Now let's look at this one over here. So this one, no clear smoke in the left atrium, but then we see that there's something sitting here. It's hazy. It's not quite clean. And then on the other image, we angle it through. We increase our angle as we rotate through the left atrial appendage. We still see it. It's not quite clear. We can't seem to get that very clean appendage that we actually like to see. So we biplane through it. And what you can see then is when you biplane, you can actually appreciate what's going on with the anatomy. There's the wall of the appendage is actually over here. We have a little bit of space behind it. And you can see that we're not, we're cutting into that wall here. And so it gives you some better visualization. And it gives you a better idea of what the anatomy is sometimes with this biplane image. Got these. OK. And so here, now we've gone to a different portion. This is the same patient. We've gone to a different portion. And now we see that there's a little bit of hazyness. And do you see the little smoke? And then we cut through here. And you can actually see there's a little bit of pooling here. There's actually a small thrombus over there, but we're in a different part of the appendage on this patient. So sometimes you go through and as you go through, you realize you're into a different part of the appendage. And that's where you're going to find some surprises sometimes. So here, you can see that there's a little bit of hazyness and it's sitting there. And there's a little bit of pooling with some clot there. All right. This last one here. So we're at the Ostium. We're a little off-axis here. You can see the appendage isn't fully open, but we see something here. And we're not quite sure where we are or what that is or if that is actually anything there. But you see something that's independently mobile. It's kind of hazy. It's not fully formed. It's very close to the front. We actually biplane it. And the biplane, you can kind of see that there might be something there. Kind of not quite sure. It's not quite formed. And could it still be artifact? We're kind of hesitating here. We do a velocity. The velocity isn't that great. The Doppler isn't that great. We don't see there that doesn't help us. So sometimes we say we can't tell and we do a CT. Yes. Can you go back on the case 7 that before, did you do the 3D on that? No, we didn't. No, we didn't. Not on that one. It's a species of a lot of clouds. I think it depends on your 2D imaging and how good your 2D imaging and what your comfort level is looking at the 3D. I think here using biplane in the multi and sort of the biplane mode of 3D is actually probably more useful than anything else. And sometimes it's very important whether you have to be... Because the surgeon and the interventionist have never thanked you for saying, I think maybe, or I'm 90% certain. They want that 100% guarantee, yes or no. So we try to just then give them a definitive answer or say you need to confirm with a CT. And that's sometimes what we've come down to. So that last case we did, we said it's very unusual. We see something there, but it would be weird for someone to be fully anticoagulated to still have something there. So then we said, do a CT with contrast, five minutes, we can get an answer. They can still get their procedure. It's very easy to add on for our radiologist here. So sometimes that's what we do. But in terms of actually getting a 3D volume, I have a case that I didn't put up. But I think sometimes 3D helps you visualize the stuff around it and if it's a clear ball and everything. Once again, it's nice, it's a pretty picture, but I'm not sure how it adds there. If you're already uncertain about it, I don't know necessarily sometimes that 3D will give you that actual little bit, especially the left atrial appendage. Yeah. All right. Good. And I think that was my last case. And then, oh, I was going to end up with this. So we talked about how the anatomy of the appendages, you can see all these little pectinate there, but sometimes you don't know whether or not it's pectinate or not. So here we have two different views. You can see there's a lot of pectinate at the tip of the appendage. And if you cut through, that can give you the reassurance that you're actually clean in your device. And it confirms what your anatomy is and what you're looking at. All right. Very good. Yeah. Oh, so no, this one has more, this one has, it's probably a big winsock. But you can see that there's lots of, it's got very deep pectinate. It's a very large there. If on-ran you use 3D in the past to look at, for some of your, for, no, for, if you want to figure out clot, you probably use bi-play button. Do you use? Right. So that's also the other thing is whether or not you'd be able to see it depending on the resolution on it. But I find multi-plane is probably the most useful. I don't know necessarily if we go into 3D for that. Very good. So sort of summary, basically, that TEE is what you actually need to look for thrombus. And the findings include a mobile, independently mobile density within the appendage. It has to move independently of the walls. Defending contrast should be something you should consider with your lab. Most, most clinical outpatient labs will have access to it. Worst case you can call and ask to borrow a vial to actually go down and do it. And sometimes they can come up and help you with that. And then pulse wave is sometimes something we do. And sometimes it's gathering all the evidence to feel comfortable with what you're going to say or not say. All right. And I'm going to actually acknowledge one of our sonographers who are helping me with pulling these cases together.