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All liver MRIs begin with a trio of localizer sequences,

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performed in the axial, sagittal, and coronal planes.

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We can see these localizers in this example over here,

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in the sagittal plane, coronal plane, and the axial plane.

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These are acquired fairly rapidly, and with a large field

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of view, we can perform them as T2-weighted sequences.

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We can also perform them as balanced gradient

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echo sequences, as seen in this example.

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Now a lot of people may not look at localizers,

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or may look at them very quickly and move

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on, but they do serve a very good purpose.

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The first thing to look for in the localizers

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is to make sure that your region of interest, i.e.,

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the liver, is well-represented in the field of view.

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So over here, we can see the portion of the liver

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is at the center of the image, and it's well

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represented and covered in these localizers.

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The second thing you want to make sure is that the

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liver actually looks nice and crisp on these images.

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So if we were to compare the first set of localizers here

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to the second set of localizers obtained after making

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a few adjustments, we can see that on the second set of

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localizers, the liver appears much more crisp, the interface

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between the liver and the lung looks much more well

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defined, and so these are better sets of sequences in

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order to use for the remaining portion of our study.

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Final thing I look for in my localizers is, because of

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the large field of view, you're getting information,

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anatomic information, from other parts of the body that

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you would not include on any of the other sequences.

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Specifically, we have images from the lungs

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obtained in the large field of view, and

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we have images obtained within the pelvis.

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And so, on all these sequences, I make sure that

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I look at the lungs and the pelvis nicely to

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ensure that there's no incidental findings that

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I need to alert the referring provider about.