 Hello, I'd like to talk to you today about MRI and valvular heart disease. My name is Gautham Reddy. I'm a professor and vice chair for academic affairs at the University of Washington. I'm going to discuss the comparison of MRI, ECHO, and CT for valvular heart disease. Also talk about valvular regurgitation, stenosis, and other valvular abnormalities. Let's start with echocardiography. This is the primary imaging modality for valvular heart disease. It's relatively inexpensive and widely available. And it's also noninvasive as is MR, and it provides adequate information in most patients. On the other hand, MRI is well-established, but it's not as commonly used as we know. The most widely available techniques are steady-state free procession, the CNA white blood technique, as well as phase contrast MRI, velocity-encoded CNA MRI, which offers highly reproducible and quantitative information. So advantages over echocardiography, MRI offers high inter-study reproducibility, and this is especially important if we are monitoring patients over time. MRI is quantitative, especially for the evaluation of regurgitation. And echocardiography is only semi-quantitative. And it also depends on estimations and assumptions about the ventricular configuration, whereas MRI directly assesses the ventricles. So let's compare MRI and echocardiography. Echocardiography is a little bit better for stenosis, primarily because of the higher temporal resolution. MRI is better for regurgitation, especially for quantification, and better for ventricular function, both in terms of quantification and following the patient's inter-study reproducibility. So what are some advantages of MRI over CT? Well, MRI, of course, does not use ionizing radiation. It requires no intravenous contrast agent. MRI is highly quantitative, especially for regurgitation. CT is developing quantitative methods, especially with retrospective gating, but the radiation dose is relatively high. NMR is more established than CT and is considered the standard of reference for evaluation of volumes and quantification of regurgitation. So these are some normal valves. This is actually just still images of the study state free procession study. We see on the top left a short axis image. This is a vertical long axis image showing the mitral valve. That's the left atrium and left ventricle. And on the three-chamber view, we see the left ventricle aortic outflow area and aortic valve, and then this is the mitral valve. No, but it is that the mitral valve and aortic valve are right next to each other. That is actually characteristic of the left ventricle. There's fibrous continuity of the anulus of the aortic valve and the anulus of the mitral valve. They're right next to each other, and they're contiguous, continuous with each other. So another still image showing the normal aortic valve with three cusps, and this is wide open, usually in a triangular shape when it opens. If it's narrowed, that suggests that there's stenosis, and I just slowed this down for you a little bit. This is a sine view showing the valves are here. This is the mitral valve. There's perhaps a little bit of regurgitation. I'm not 100% sure, but it suggests that with this blackness right there, and then this is the tricuspid valve, which opens and closes quite nicely. Okay, so now let's look at this patient. What do you think about this? This patient is image in an oblique coronal view, coronal plane, and this is the left ventricle, functioning quite well. Look at the aorta. The isening aorta is abnormal, especially the aortic root is markedly dilated until the sinus tubular junction, and then it becomes more normal. So when we see root dilation in the aorta, that is consistent with annulo aortic ectasia as seen in Marfan syndrome, and one of the complications of annular ectasia, what are the three major complications? One is dissection, one is aortic rupture, and another one is aortic regurgitation. What do we see here? This is the aortic valve, and this is the black flow jet emanating from the valve into the left ventricle during diastole, and that is consistent with regurgitation. So the patient has a substantial regurgitation, and this is called spin defacing the black flow jet. So the most likely diagnosis, well, I gave it away, it's regurgitation. So we see this here again, aortic regurgitation, the valve is right here, in a patient with annular ectasia and Marfan syndrome. So the same patient in this situation, the aortic root is seen in plane. You can see that it opens quite nicely as a triangle. It's markedly dilated, but look at it as it's closing, as it closed. We still see a small hole right there. So that indicates that the leaflets are not co-acting properly or completely, and that is what is causing the regurgitation. So what are some etiologies of regurgitation, well, degeneration, coronary artery disease especially in the mitral valve, endocarditis, rheumatic heart disease, especially in the aortic valve. The rheumatic heart disease is relatively common around the world. It's not as common in industrialized countries because of the widespread use of antibiotics. And then annular ectasia, which is relatively rare, as I said, this is associated with Marfan syndrome, and it causes aortic regurgitation. So let's look at this patient. This is a different patient. It was a markedly enlarged right ventricle, and a right atrium is also enlarged. Look at the left ventricle. It's relatively small with marked compression and straightening of the septum. So what is the cause of this? You can see here this black fluja, the spin-de-phasing, and that is occurring during systole indicating tricuspid regurgitation, and it's substantial. Now, this is an acquired disease, but in this particular patient, it's a different patient here, we see the same thing, tricuspid regurgitation. This is a patient who has Epstein anomaly. And in Epstein anomaly, the tricuspid valve is abnormal. Two of the leaflets are displaced towards the apex. So there's gross tricuspid regurgitation, and that's what we're seeing here. Notice, again, the RV and the RA are markedly enlarged. There's straightening of the septum, another finding that we see in RV enlargement. And think about it. Why don't we usually see the RV this big when there's regurgitation? Because the RV is more compliant. It just expands readily, much more so than the left side. OK, this is a patient who has mitra regurgitation here, and then this is a little bit of tricuspid regurgitation as well. Now, let's move on and talk about quantification. How do we quantify? I mentioned earlier that MRI has an advantage of quantification in the setting of regurgitation. Well, what we do most commonly, we use the phase contrast imaging for arid valve regurgitation. And we also do this for pulmonary regurgitation. Pulmonary regurgitation is not as common, but we do see it in congenital heart disease, especially after repair of Tetralogy of Fallot. So let's look at this patient. The top images, this is phase contrast velocity encoded Cine MRI. The top row is magnitude, the bottom row is phase. So magnitude shows anatomy and phase shows the velocity and flow. So look at the ascending aorta here. This is during systolee. And notice that the ascending aorta has forward flow, which is depicted as white signal, as bright signal. And during diastolee, this is the ascending aorta, and there's no flow because the valve has closed. This is normal. It's gray there, indicating no flow. So, and this is the flow curve. This is forward flow during systolee and no flow during diastolee. And most arteries, other than the coronaries, the arteries have their, most of their, they have their flow during systolee, essentially goes to zero during diastolee. This is normal. Now, how about a different patient here? Look at the ascending aorta during systolee. There's forward flow depicted as white during diastolee. What happens? It's depicted as dark as black signal. So it is reversal of flow. It's not the normal gray. And this is the flow curve. There's forward flow during systolee and reversal of flow during diastolee. This is the regurgitation. So let's look at that again. So forward, forward flow here, regurgitant flow here. The area under the curve here is the regurgitant or retrograde flow. That's the regurgitant volume. If you divide regurgitant volume by forward volume or anti-grade volume, that equals the regurgitant fraction. And regurgitant volume and regurgitant fraction are key indices for us to be able to evaluate quantitatively and to report. So another patient, so this patient, another patient, has severe pulmonary regurgitation after tetralogy of flow repair. And you can see here that there is a regurgitant jet right here in the RV alpha tract. And we can quantify that using the phase contrast study. This is forward flow and reversal of flow in the pulmonary artery. And we can see that here. This is the baseline. This is zero. This is forward flow and reversal of flow just as we saw in the patient with a regurgitation. And we can also calculate ejection fractions in these patients. I discussed this in an earlier talk in which we draw the endocardial line during end diastole and end systole. And we're able to determine stroke volume and injection fraction and diastolic volume and systolic volume. So that's helpful in patients with regurgitation as well. Let's turn our attention now to another mitral valve disease prolapse. So notice here that there is posterior bulging of the mitral valve. And one way to determine prolapse is the insertions of the mitral valves are here. If we draw a line here, the mitral valve is bulging backwards. That's an indicator of prolapse. And notice that the patient also has something else, this black flow jet, which is a regurgitant jet of spin defacing. So mitral prolapse. And they also happen to have mitral stenosis. And this is myxomatous mitral prolapse. Another patient with myxomatous mitral prolapse. We can see a similar finding of this posterior bulging here and here as well with the regurgitation. So let's turn our attention now to stenosis. What are some causes of aortic stenosis? Well, degenerative disease, rheumatic heart disease, and congenital bicuspid aortic valve. These are the most common causes of aortic stenosis. So this is an image of a patient with a markedly thickened and irregular aortic valve. It's very likely to be calcified and it's barely moving, indicating severe stenosis. Look at the posttonotic flow jet, the black jet of spin defacing, another indicator of stenosis. So this patient has three leaflet aortic stenosis here. Notice that it hardly opens. Instead of the nice big triangle, we just see this little, the little opening of the cusps. Okay, so, and this is a different patient. So notice here that there were three leaflets. One, two, and three. In this patient, what do we see? We only see two leaflets here and here. And this opening up is called the fish mouth appearance because it has the look of a fish's mouth right there. Okay, so that's opening very wide. So it's not stenotic. But as I said, bicuspid aortic valve is a common cause of aortic valve stenosis. This is a different patient with bicuspid valve. Notice that the aortic valve is barely moving here. And there is a spin defacing artifact, the black flow jet indicating stenosis. And look at the valve in plane. It is barely moving. It's thickened, irregular, indicating calcification. And it's dark, another indicator of calcification. It's barely opening. This is still the fish mouth appearance. We can see one cusp here, one here. And the fish's mouth right here. But this fish is not very hungry. It's barely opening its mouth. And that's when you see that appearance, think bicuspid aortic valve stenosis. Okay, so another patient with bicuspid aortic valve. Notice that there's one cusp here, one here. It's a little bit hard to tell when it's not moving, but it's a very narrow opening here. So another fish that's not very hungry, so stenotic bicuspid valve. And this is a patient with coarctation of the aorta. We can see the coarctation here on the Gettolinium enhanced MRA. So coarctation is one of the entities that's associated with bicuspid valve. Bicuspid aortic valve is actually the most common congenital anomaly of the heart. And it usually stands alone. It doesn't have associated anomalies. It doesn't have other anomalies. But in some patients, there are associations such as coarctation. It can also be seen in Turner's syndrome and in Shown's complex. The coarctation is the most common anomaly that's associated. We talked about this in another talk, which is quantification of the pressure gradient in stenosis using the modified Bernoulli equation. Remember the pressure gradient delta P equals 4V squared. And if we use the units for the peak velocity of meters per second, then we can derive pressure gradient in millimeters of mercury. So in this particular patient, look at the peak velocity or look at the velocity during the cardiac cycle. It peaks here. And that peak velocity is about 260 centimeters per second or 2.6 meters per second. So that's V. If we square V, multiply by four, we derive the pressure gradient, which is 27 millimeters of mercury. Another way to quantify the severity of stenosis is to do planimetry, which is essentially determining the area of the opening here. And you can see markedly stenotic aortic valve right there. And then we determine how big this opening is. It's very small. It's 148 square millimeters. So this is known as Sam or systolic anterior motion of the mitral valve. So in hypertrophic cardiomyopathy, one of the associated entities is systolic anterior motion of the mitral valve. And this particular leaflet, the anterior leaflet, which is seen here is pulled anteriorly during systole. Notice that there's thickening of the interventricular septum that frequently occurs in hypertrophic cardiomyopathy. That occurs in about 90% of individuals with hypertrophic cardiomyopathy, this asymmetric septal hypertrophy. And that impinges on the LV-alpha trap, which is right here. So this impinges. In addition, some patients, a small number of patients, have this systolic anterior motion of the mitral valve. This anterior leaflet gets pulled anteriorly just as it actually needs to be patent here. This area, the alkyl tract needs to be patent instead, this blocks it. So this becomes very narrow during systole and that causes functional abnormality. It also will cause regurgitation. So let's look at that again. You can see this gross narrowing here during systole, because this anterior leaflet is pulled forward and it's this black area right there that's being pulled forward. And then we also see the flow jet here, which is the regurgitant jet. Okay. So another patient with systolic anterior motion and mitral regurgitation, we see the mitral regurgit here. Also there's narrowing of the alkyl tract. So there's this black flow jet in the aortic area as well. So now let's talk about endocarditis. This patient's mitral valve endocarditis. Now alkyl cardiography is much better than MRI for evaluation of endocarditis for identification and diagnosis. Occasionally we do see it with MR. Notice that there's vegetation on the mitral valve itself. This is pulmonary valve endocarditis right here. A right-sided endocarditis is most often seen in patients who use IV drugs will inject drugs through the veins. So this is what occurs. And then these patients can also get septic emboli after this endocarditis develops. So they need to have antibiotics usually for multiple weeks up to six weeks of intravenous antibiotics. Okay, and look at this patient with the mitral valve endocarditis and what else do they have? The large pulmonary emboli. And as I said, they can develop septic emboli. So a different patient. This is a tumor on the mitral valve. It turns out to be a myxoma. That's one of the tumors that commonly involves the left atrium. But it can also be on the valve. It can be pedunculated off of the valve or it could be a set valve sitting right on the valve and it will move with the valve. It may prevent proper closure of the valve. So myxoma is an important diagnosis to think about when we see mitral valve tumors. This is a different patient with another tumor called fibroelastoma. And I'll talk about this more in the talk on tumors, but what we do is use delayed hyper enhancement or late gadolinium enhancement sequences with a long TI. I'm sorry, this should be TI or inversion time of 600 milliseconds. The thrombus becomes darker. The tumor becomes brighter and this became brighter. So that is a tumor and it happens to be a fibroelastoma, which is another tumor that occurs on the valve. So in conclusion, MRI is highly accurate for quantification of valvular disease, especially of regurgitation. MRI can be applied to the assessment of stenosis and echocardiography is the mainstay of valvular heart disease, but MR has specific roles, especially for quantification. And MR can be used to evaluate endocarditis if echo is suboptimal and to differentiate a thrombus or endocarditis from tumor. So there are specific defined roles for MRI. We don't use it in all of the patients, as we know, but there are some patients who can benefit from an MR study of the valve. Thank you very much for your attention.