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Thank you for the introduction. My name is Chris Walker and

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I'm a cardiothoracic radiologist at the University of Kansas

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Medical Center.

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So today I'm going to be talking about cardiac MRI and we'll

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be going through several cases related to masses infiltrative

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disorders and then kind of

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specifically focusing on Lake edelenium enhancements.

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These are my disclosures which aren't really relevant to this talk today.

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And so before we get into the cases, I just wanted to briefly just

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kind of discuss cardiac MRI and

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then what exactly we're looking for?

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And so the most important sequence that we do with cardiac imaging

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is going to be the steady state free procession cinequences.

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This has a variety of different names depending

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on the vendor Fiesta with GE

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true-fifths with Siemens. And this occurs is

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a sequential Imaging at one slice as a

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breath hold acquisition in the

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way that we acquire these images is using segmented case space.

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And so when I'm talking about segmented case space essentially

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we have EKG leads on the patients and we're

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acquiring different frames of each part of

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the cardiac cycle. And so these are

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a few different beats over the cardiac cycle and it

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requires several different EKG or

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several different heartbeats to acquire the entire image. And

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so as we're Imaging here, you can see that we're filling up

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case space.

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And after several cardiac Cycles were

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allowed were essentially we are able

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to image the heartbeat as it beats

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during the cardiac cycle. And so

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this is what essentially the segmented case space acquisition.

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represents

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and so again, the Workhorse of cardiac imaging is going

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to be the cine steady state free procession Imaging. These are the

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bright blood sequences.

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We typically acquire them in several different planes. And

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so the short axis image allows us

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to see the left ventricle and the right ventricle.

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The four chamber image allows us to see the four different chambers. So

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the left atrium the left ventricle the right

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ventricle and the right atrium and then left

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ventricular also attract allows us to see the left atrium the

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left ventricle as well as the aorta.

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In really the goal of the sequence here is to assess wall

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motion to look for both Global wall

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motion abnormalities as well as Regional wall motion abramalities to

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assess cardiac function and then to look

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at the valves.

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The double inversion recovery sequences can be either T1 or

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T2 weighted and these referred to as the black

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blood sequences and the goal of these sequences to look

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at pericardial thickness the anatomy as

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well as any Mass signal intensity. So if you have

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a cardiac Mass, it's helpful to look at the Double inversion recovery sequences

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to try to decide what is the mass imposed

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of

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The triple inversion recovery sequences at a

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third inversion time essentially to null

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fats within it. So these will be fat sack

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images and really the goals of these different

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sequences are to look for any sort of myocardial edema.

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So if you're looking for a myocarditis patient as in

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the setting of inflammation, it also allows us to characterize a

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mass.

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These are fairly difficult to interpret. These

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are two different triple inversion recovery sequences

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from different patients. This one is a melanoma metastasis

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here kind of the wall the left atrium

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and this is just a short axis image.

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Commonly, you get this kind of artifact here

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within the trabeculation which is from slow flow

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within the trabeculation. And so you have

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to be very cautious to not interpret that as

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edema within The myocardium, but rather just within

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the trabeculation is just kind of a slow flow artifact.

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And then really kind of the main sequence another main

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sequence that we do with cardiac MRI is going to be the post-gadolinium enhanced

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images. And so we inject catalinium contrast

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usually double-strength contrast. So 0.2 millimoles

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per kilogram. You may do initial first

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past perfusion. Imaging which is shown here on the right where

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we've injected the gadolinium and then we're just watching it

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profuse Through The myocardium. If you have a mass characteristic

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this can allow for kind of first past perfusion,

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imaging of the mass itself to see that enhances.

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And the kind of the take home here is that in schemic or

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infarctic? Myocardium will often hypo enhance on the first

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pass for Fusion Imaging. So in the short axis image, you

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can see the contrast going into the left ventricle perfusing Through

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The myocardium and then you can see this hypoenhancing band

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here in the LED territory secondary to

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a severely stenotic or included left

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anterior descending coronary artery.

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And then we generally will wait 10 to 15 minutes to start

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the lake gettellinium enhanced images after giving contrast.

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And so the purpose of Lake adalenium enhancement. This is also referred

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to as the late enhancement. This was

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initially used in patients to look at myocardial infarction.

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And the whole purpose is here is that

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contrast is going to be trapped in areas of Scar or

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potentially infiltrated disorders. So myocardial infarction

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will light up.

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As well as other disorders such as sarcoidosis amyloidosis

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myocarditis and then neoplasms.

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And we essentially do these again

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after usually waiting 10 to 15 minutes after

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injecting the gadolinium. And if you look here at

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these curves essentially The infarcted myocardium will

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have a different inversion time in both the schemic

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and normal myocardium and so by waiting this, you

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know, seven to 10 minutes 10 to 15 minutes it

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allows us to

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Essentially tell the difference and so that we can actually image that

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difference.

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And so what these are these are a single inversion sequence

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GRE sequence where

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we basically hit the hit all the protons with

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a single inversion time. And as it relaxes

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back, you'll see that normal myocardium and infected myocardium

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as well as infiltrated disorders will

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have a different relaxation time back to the Baseline and

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this is what we're essentially trying to look at. So

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you want to pick an inversion time where the normal myocardium is

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known or turns black.

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This is a simian version recovery sequence or a look

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Locker sequence that basically has increasing ti times.

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And so as we increase the ti time,

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you can see that normal. Myocardium will become black at around

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180 milliseconds. And so that's the time that

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we pick in this case to image The myocardium for

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the lake edelenium enhanced.

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Sequence and so we run that a sequence. We're normal. Myocardium is black

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and then abnormal myocardial will show up as bright as

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in this case and so once he picked that TI time you

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run the sequence through the heart typically in the short axis plane

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as well as other planes to for confirmation of defects.

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In the rule here is that abnormal? Myocardium is going to show

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up as bright. And so you want to look at the distribution to see

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if it follows a vascular territory. If it

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doesn't follow vascular territory, you're dealing

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with non-ischemic like metal and even enhancement and that really

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helps with the differential diagnosis as you'll see in the following cases.

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And so here is how I kind of approach these

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cases. I looked I like to look at the cine Clips

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first to determine if there's any wall motion abnormalities. Remember,

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we will describe all motion abnormalities is

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global. So is the entire ventricles Contracting

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as well as Regional while motion abnormalities, we'll

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look at the anatomy the function and

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then the wall thickness of the left ventricle. Is it too

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thin too thick is that wall thickness focally thin

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or focally thick or is it diffusely thickened and

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then also they need the alveolar abnormalities. We'll

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review the double in the triple inversion recovery sequences

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mainly to characterize masses as well

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as to look for any edema in the setting a myocarditis.

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And then finally, we'll focus on these Lake edelenium enhanced

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images to determine the distribution trying to

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separate any enhancement into ischemic as

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well as non-ischemic patterns.