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Warm greetings to all viewers.

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My name is Mahan Mathur.

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I'm an Associate Professor of Radiology and Biomedical

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Imaging at the Yale School of Medicine, and this course is

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going to cover the MR evaluation of benign liver lesion.

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This first section will serve as a brief introduction, a

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roadmap, if you will, of the content that is to follow.

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Before we get going on any learning opportunity, I always

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find it very important to answer the question, why?

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Why is this topic critical for you to know?

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Well, it turns out that liver lesions are very common.

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If we look at all imaging studies, by some

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estimates, you're going to see an incidental

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liver finding in about one third of them.

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So it's something you're going to encounter

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commonly in your clinical practice.

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The second why you may have to

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answer in this case is, why MRI?

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Well, MRI has really proven to be the

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definitive non-modality in evaluating

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liver lesions for a number of reasons.

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First and foremost, there is increased soft

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tissue resolution when you compare this to any

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other imaging modality out there at the moment.

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It allows us to see areas of subtle, subtle enhancement

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within liver lesions, which is extremely important

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as we'll see over the course of this, uh, course.

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Of course, MRI has no radiation, so we like that.

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It's an advantage of using MRI.

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And we can also use a variety of different contrast agents

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with MRI that allows us to offer some increased specificity.

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Regarding the lesions that we encounter.

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During this course, we're going

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to counter a bunch of lesions.

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We're going to talk about a variety

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of cystic lesions seen in the liver.

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We're also going to be covering the varying

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imaging appearances of one of the more common

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imaging lesions, that is the hemangioma.

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nodular hyperplasia and liver adenomas.

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Now, these are lesions that happen

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in similar patient demographics.

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So we'll talk about how do we differentiate them

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and why is it important to differentiate them.

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We're also going to cover the appearance of focal

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fat, the deposition within the liver, which is a

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pseudo lesion that can mimic, uh, other liver lesions.

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And finally, we're going to cover some infectious

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causes in the liver, such as hydatid cysts.

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Now, before we get to the fun stuff and talk about all the

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liver lesions, it's important to talk a little bit about the

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sequences that we're going to be utilizing for liver MRI.

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Now, when anyone starts off interpreting liver

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MRI, I find that, um, they may be intimidated

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by the number of sequences that you encounter.

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But, with a little bit of practice, you'll realize

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that you're really dealing with only about 10

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sequences, and we can sort of split them into four

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groups of sequences that you need to evaluate.

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The first one are the localizers, which are done in

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all liver MRIs, followed by T2-weighted sequences.

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We then look at the T1 in and out of phase sequences.

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Finally, the T1 pre- and post-contrast sequences.

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So, There's the introduction and the

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roadmap that will follow as we encounter

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the remaining content within this course.