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This is a FLAIR flare MR image

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from a ten-month-old with

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tuberous sclerosis complex.

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The tuberous sclerosis complex was identified

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on prenatal imaging with a cardiac rhabdomyoma,

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and subsequent genetic testing confirmed it.

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So, it's known that the patient has tuberous sclerosis complex.

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Now, at ten months of age,

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They are performing an MRI of the brain

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to see what the intracranial involvement is.

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So this FLAIR image,

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we're not necessarily, at first glance,

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not seeing anything major.

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We see a little subependymal nodule here.

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We see another subependymal nodule.

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So as we look through it, as we look closer,

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we're seeing some juxtacortical signal

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abnormality in the left frontal pole,

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in the left temporal lobe.

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Now, we're seeing some cystic areas at the junction

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of the left temporal and occipital lobes.

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So, it's not normal.

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So, there are intracranial manifestations

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of tuberous sclerosis complex.

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But note that this is,

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while this is a FLAIR image,

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the white matter is sort of hyperintense.

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We usually aren't used to seeing

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the white matter look like that on FLAIR.

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That's because at this age,

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at nine and ten months of age,

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the brain is partially myelinated.

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So, FLAIR can look very unusual.

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So, if we look at T2-weighted imaging,

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we can see multifocal areas

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of cortical dysplasia,

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much more so than we would suspect on FLAIR.

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So on the FLAIR,

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we see this little crescentic area of

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juxtacortical signal abnormality.

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But that corresponds to this area here

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on the T2-weighted image.

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But these multifocal additional areas on T2,

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you can barely tell on FLAIR.

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So, this just goes to show understanding what

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imaging sequences to use at a given

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age of development is important.

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Now, in neonates,

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where they're completely unmyelinated.

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T1-weighted imaging is typically the best way

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to look for areas of cortical dysplasia

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in tuberous sclerosis complex.

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Well here, we can see this bright signal.

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That bright signal is related

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to ongoing myelination.

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It's hyperintense T1-weighted imaging

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from the proteolipids of myelin.

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And so, we're not really seeing the

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T1-weighted manifestation of cortical dysplasia.

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At this stage of intermediate myelination,

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T1-weighted imaging underestimates

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the lesion burden,

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even though T1-weighted imaging is

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the preferred method in a newborn.

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FLAIR imaging underestimates the abnormality

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in this nine to ten month age window,

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given the ongoing myelination,

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even though FLAIR imaging is the most commonly

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used for maturely myelinated individuals.

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So T2-weighted imaging itself,

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without any inversion pulse,

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ends up being a very effective way of

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evaluating dysplasia,

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especially with

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a mixed ongoing myelination pattern.

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Now, it also shows these subependymal nodules.

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So, this is a patient who's ten months

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of age with tuberous sclerosis complex,

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where the T1-weighted imaging,

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you typically used in a newborn,

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typically used in a mature myelinated individual,

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underestimate the lesion burden.